B3 SESAR JU PROJECT
Phase Two Report
– Phase 2 Version 4.2 - 15/02/2012- Page i
B3 SESAR JU PROJECT
TABLE OF CONTENTS TABLE OF CONTENTS .................................................................................................................. 2 LIST OF FIGURES.......................................................................................................................... 6 LIST OF TABLES ......................................................................................................................... 12 EXECUTIVE SUMMARY............................................................................................................... 13 1. 1.1 1.2 1.3 1.4 2. 3. 3.1
FOREWORD ....................................................................................................................... 1 ABOUT THE DOCUMENT .................................................................................................. 1 THE AUTHORS ................................................................................................................... 1 STRUCTURE OF THE DOCUMENT ................................................................................... 1 GLOSSARY ........................................................................................................................ 2 INTRODUCTION ................................................................................................................. 3 DESCRIPTION OF THE SOLUTION TO LEAD TO THE PROOF-OF-CONCEPT ............... 4 DESCRIPTION AND PROOF OF CONCEPT ...................................................................... 4
3.1.1 3.1.2 3.1.3 3.1.4 3.1.5
VERTICAL FLIGHT PROFILE – TYPICAL ................................................................................... 4 DESCENT – GENERAL PRINCIPLES ......................................................................................... 6 IMPACT OF NON-ADHERENCE TO THE CALCULATED DESCENT PROFILE ....................... 8 IMPACT ON FUEL-BURN OF A PARTIAL CDO - PROFILE ..................................................... 10 KNOWLEDGE OF DESCENT PATH BY THE ANSP................................................................. 13
3.2 ACHIEVEMENT OF THE PROJECT ................................................................................. 16 3.2.1 THE CDO CHALLENGE ............................................................................................................. 17 3.2.2 EUROCONTROL APPROACH TO CDO ................................................................................... 18 3.2.3 OBJECTIVES OF THE B3 PROJECT ........................................................................................ 18 3.2.4 REFERENCE FOR CDO AT EBBR (BELGOCONTROL & BRUSSELS AIRLINES)................. 19 3.2.4.1 General ................................................................................................................................ 19 3.2.4.2 Belgocontrol ......................................................................................................................... 21 3.2.4.3 Brussels airlines .................................................................................................................. 22
3.3 THE FLIGHT TRIAL PERIOD............................................................................................ 23 3.3.1 PHASE ONE ............................................................................................................................... 23 3.3.2 PHASE TWO .............................................................................................................................. 23 3.3.2.1 transition into operations ..................................................................................................... 24 3.3.2.2 pace of change .................................................................................................................... 24
4.
DATA COLLECTION PROCESS, TOOLS AND ANALYSIS ............................................. 25 4.1 OVERVIEW ....................................................................................................................... 25 4.2 DATA SOURCES .............................................................................................................. 27 4.2.1 NMS (NOISE MONITORING SYSTEM) ..................................................................................... 27 4.2.2 CDO TROUBLE REPORTS ....................................................................................................... 27 4.2.2.1 CDO – trouble reports (Brussels Airlines pilots) .................................................................. 27 4.2.2.2 CDO – trouble reports (ATCOs) .......................................................................................... 27 4.2.3 FLIGHT LISTS WITH INDICATION OF CDO-MARKED FLIGHTS ............................................ 28 4.2.3.1 Marking CDO-approved flights ............................................................................................ 29
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B3 SESAR JU PROJECT 4.2.3.2 Extracting Flight data from Eurocat-logfiles for CDO-flights................................................ 30 4.2.3.3 Correlate Eurocat-data with REDSTAR-flight data ............................................................. 31 4.2.3.4 Distribute flight lists with indication of CDO-marked flights ................................................. 32 4.2.4 ASTERIX CAT62 RADAR DATA ................................................................................................ 32 4.2.5 FDM-DATA ................................................................................................................................. 33 4.2.5.1 Setting of the Concept ......................................................................................................... 33 4.2.5.2 Technicalities and limiting factors ........................................................................................ 34 4.2.5.3 Extraction of FDM-data – in house development of an algorithm ....................................... 35
4.3 TOOLS .............................................................................................................................. 37 4.3.1 NMS (NOISE MONITORING SYSTEM), SAS AND GIS ............................................................ 37 4.3.1.1 Description of the NMS........................................................................................................ 37 4.3.1.2 NMS-reports as a reference for airlines and Belgocontrol .................................................. 38 4.3.1.3 NMS-radardata to compare lateral routes for CDO-approved and non-CDOapproved flights using SAS and GIS ................................................................................................... 40 4.3.2 EFICAT ....................................................................................................................................... 40 4.3.2.1 CDO-evaluation by EFICAT ................................................................................................ 40 4.3.2.2 Fuel burn analysis possibilities with EFICAT....................................................................... 42 4.3.2.3 Radar-data visualization in EFICAT .................................................................................... 43 4.3.2.4 Agreement with Eurocontrol to test the EFICAT tool .......................................................... 45 4.3.2.5 Import of radar data in EFICAT for the B3-project: ............................................................. 45 4.3.2.6 EFICAT Analysis performed for B3-project ......................................................................... 46 4.3.2.7 Export of the EFICAT results to MS Excel for further analysis............................................ 47 4.3.3 SQL &MS EXCEL FOR THE STATISTICAL ANALYSIS OF CDO-APPROVALS AND OF EFICAT-RESULTS .................................................................................................................................... 48 4.3.4 MS EXCEL FOR DESCENT PROFILE ANALYSIS OF FDM-DATA .......................................... 48 4.3.4.1 Use of FDM-parameters. ..................................................................................................... 48 4.3.4.2 Reference profile construction. ............................................................................................ 49 4.3.4.3 Analysis description. ............................................................................................................ 50 4.3.5 INM (INTEGRATED NOISE MODEL) FOR NOISE CALCULATION ......................................... 55 4.3.5.1 Calculation model ................................................................................................................ 55 4.3.5.2 General calculation method of the INM ............................................................................... 56 4.3.5.3 Method USED to compare the noise impact of CDO and non-CDO approaches ............... 59
5.
4.4 SELECTION OF DATA SAMPLE FOR DETAILED ANALYSIS ........................................ 63 DATA ANALYSIS RESULTS ............................................................................................ 65 5.1 SCOPE OF THE TRIALS - 1 JULY 2009 – 31 OCT 2011 ................................................. 65 5.1.1 5.1.2
DESCRIPTION ........................................................................................................................... 65 SUMMARY AND CONCLUSION FOR POINT 5.1 ..................................................................... 67
5.2 CDO-MARKED FLIGHTS - 1 JULY 2009 – 31 OCT 2011 ................................................. 68 5.2.1 5.2.2 5.2.3 5.2.4 5.2.5 5.2.6 5.2.7 5.2.8 5.2.9 5.2.10
CDO MARKED FLIGHTS PER AIRLINE .................................................................................... 68 EVOLUTION DURING THE TRIAL PERIOD ............................................................................. 70 VARIABILITY FROM DAY TO DAY............................................................................................ 72 VARIABILITY AMONGST THE HOURS OF THE DAY .............................................................. 73 VARIABILITY AMONGST THE WEEKDAYS ............................................................................. 75 COMPARISON FOR RUNWAYS 25R AND 25L ........................................................................ 77 FLIGHT LEVELS AT WHICH CDO IS APPROVED ................................................................... 79 TRACKMILES FROM TOUCHDOWN AFTER CDO APPROVAL ............................................. 81 EFFECT OF THE CHANGE FROM WRITTEN TO CLICKED CDO-MARKS ............................ 83 SUMMARY AND CONCLUSION FOR POINT 5.2 ..................................................................... 85
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B3 SESAR JU PROJECT 5.3 CDO-PERFORMANCE (EFICAT-ANALYSIS) – APRIL & MAY 2011 ............................... 86 5.3.1 CDO-CRITERIA USED ............................................................................................................... 86 5.3.1.1 Parameter Setting ................................................................................................................ 86 5.3.1.2 Classification in four groups of CDO-performance .............................................................. 87 5.3.1.3 Data sample for statistics in section 5.3 .............................................................................. 89 5.3.2 CDO-PERFORMANCE (PROFILES) ......................................................................................... 90 5.3.2.1 All airlines, all runways ........................................................................................................ 90 5.3.2.2 All airlines , runways 25R/L ................................................................................................. 91 5.3.2.3 Marked versus Not Marked for all airlines ........................................................................... 91 5.3.2.4 Marked versus not marked for participating airlines ............................................................ 92 5.3.2.5 Comparison for runway 25 R & 25L .................................................................................... 93 5.3.3 CDO-PERFORMANCE (PROFILES) FOCUS ON BRUSSELS AIRLINES ............................... 94 5.3.4 FUEL AND CO2 ESTIMATIONS WITH EFICAT ........................................................................ 98 5.3.5 FUEL AND CO2 ESTIMATIONS WITH EFICAT COMPARED TO FDM-FUEL DATA ............ 104 5.3.6 SUMMARY AND CONCLUSION FOR POINT 5.3 ................................................................... 106
5.4 RESULTS OF CDO TROUBLE REPORT (ATCOS). ....................................................... 108 5.5 RESULTS FROM FDM-ANALYSIS ................................................................................. 109 5.5.1 5.5.2 5.5.3
EXAMPLES............................................................................................................................... 109 RECURRENT OBSERVATIONS .............................................................................................. 117 OVERVIEW OF RESULTS. ...................................................................................................... 123
5.6 CALCULATED NOISE IMPACT ...................................................................................... 135 5.6.1 NOISE IMPACT CALCULATION – TYPICAL EXAMPLE ........................................................ 135 5.6.2 AREA OF THE LAMAX NOISE CONTOURS .............................................................................. 139 5.6.2.1 Airbus 330-330 analyzed flights ........................................................................................ 139 5.6.2.2 Airbus 319 analyzed flights................................................................................................ 146 5.6.3 LAMAX-NOISE PROFILES .......................................................................................................... 152 5.6.3.1 Airbus 330-330 analyzed flights ........................................................................................ 152 5.6.3.2 Airbus 319 analyzed flights................................................................................................ 157 5.6.4 IMPACT ON LATERAL ROUTES ............................................................................................. 161 5.6.5 CONCLUSION NOISE ANALYSIS ........................................................................................... 164
6.
COMMUNICATION PLAN ............................................................................................... 165 6.1 IMPLEMENTED COMMUNICATION ACTIONS DURING PHASE 2 ............................... 165 6.1.1 6.1.2 6.1.3 6.1.4
BELGOCONTROL .................................................................................................................... 165 BRUSSELS AIRPORT .............................................................................................................. 167 BRUSSELS AIRLINES ............................................................................................................. 167 OTHER ..................................................................................................................................... 168
6.2 PLANNING OF COMMUNICATION ACTIONS AFTER DELIVERY OFPHASE 2 ........... 168 7. THE FUTURE .................................................................................................................. 170 7.1 FROM TRIALS TO IMPLEMENTATION.......................................................................... 170 7.2 PROJECT POINT MERGE BRUSSELS .......................................................................... 170 7.2.1 PROJECT OBJECTIVES .......................................................................................................... 170 7.2.2 THE POTENTIAL BENEFITS ................................................................................................... 174 7.2.2.1 For ATC : ........................................................................................................................... 174 7.2.2.2 For the Airlines and Airport Operators : ............................................................................. 174
APPENDICES ............................................................................................................................. 176 APPENDIX 1 - DEFINITION OF FLIGHT PHASES FOR AIRBUS FMS .................................. 177 APPENDIX 2 – DESCENT PROFILE BASICS. ....................................................................... 178 – Phase 2 Version 4.2 - 15/02/2012- Page iv
B3 SESAR JU PROJECT VERTICAL FLIGHT PROFILE – TYPICAL ............................................................................................. 178 RELATION TO THE SESAR – “BUSINESS TRAJECTORY” ................................................................. 182 The background................................................................................................................................. 183 Implementing 4D trajectories ............................................................................................................. 183 DESCENT – GENERAL PRINCIPLES ................................................................................................... 184 Mach/CAS descent ............................................................................................................................ 184 Descent speeds – example ............................................................................................................... 186 IMPACT OF NON-ADHERENCE TO THE CALCULATED DESCENT PROFILE .................................. 188 IMPACT ON FUEL-BURN OF A PARTIAL CDO - PROFILE ................................................................. 192 KNOWLEDGE OF DESCENT PATH BY THE ANSP ............................................................................. 195
APPENDIX 3- DESCENT PROFILES FOR AIRBUS A320 AND A330 AIRCRAFT ................. 198 APPENDIX 4 – DESCENT SCENARIO – AIRBUS AIRCRAFT. .............................................. 199 APPENDIX 5 – AIRBUS A319 - AFM REFERENCE DESCENT PROFILES. .......................... 203 APPENDIX 6 – AIRBUS A330-300 - AFM REFERENCE DESCENT PROFILES. ................... 205 APPENDIX 7 -DRAFT CDO PUBLICATION ............................................................................ 207 VALIDATION DATE OF PREPARATION ............................................................................................... 207 EBBR AD 2.21 NOISE ABATEMENT PROCEDURES........................................................................... 207 ARRIVAL PROCEDURES ................................................................................................................. 207 SPEED LIMITATION ......................................................................................................................... 207 EBBR AD 2. 24 CHARTS RELATED TO EBBR ............................................................................... 208
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B3 SESAR JU PROJECT
LIST OF FIGURES Figure 2-1 - Typical vertical profile Figure 2-2 - Simplified descent profile. Figure 2-3 - Location of the "Top-of-Descent" Figure 2-4 - TOD penalties. Figure 2-5 - Airbus A330-300 – M.80/300KT/250KT descent profile and fuel burn. Figure 2-6 - Initiation of a CDO at or below FL150. Figure 2-7 - Example of descent profile and fuel burn below FL150 - Airbus A330-300. Figure 2-8 - Different descent profiles. Figure 2-9 - Descent profiles below FL150 for A330-300. Figure 2-10 - Difference 3 to 4° glide path. Figure 2-11 - Descent optimization. Figure 2-12 - CDO approach. Figure 3-1 - Data Collection scheme legend. Figure 3-2 - Data Collection scheme. Figure 3-3 - CDO Trouble Report. Figure 3-4 - Marked-field on CWP. Figure 3-5 - Marked-field on CWP (2). Figure 3-6 - VPFC. Figure 3-7 - HPFC. Figure 3-8 - Visual detection of a non-CDO (VPFC). Figure 3-9 - Figure 5.9 : Visual detection of a CDO (VPFC). Figure 3-10 - EFICAT Analysis part1. Figure 3-11 - EFICAT Analysis part2 (scrolled to the right). Figure 3-12 - EFICAT – Example of Horizontal Plot. Figure 3-13 - EFICAT - Example of Vertical Plot. Figure 3-14 - EFICAT - Example of Perspective Plot. Figure 3-15 - Reference Descent Profiles. Figure 3-16 - Typical Descent Profile graph. Figure 3-17 - Typical Descent Profile – Time graph. Figure 3-18 - Typical Descent Profile – distance graph. Figure 3-19 - Typical Fuel Burn below FL150 graph. Figure 3-20 - INM 7.0b noise-thrust-distance curves for approach of the Airbus 330301 with GE CF6-80 E1A2 engines. – Phase 2 Version 4.2 - 15/02/2012- Page vi
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B3 SESAR JU PROJECT Figure 3-21 - Determination of the shortest receiver – ground-track distance during approach. Figure 3-22 - INM 7.0b standard approach profile for the Airbus A330-301 (thrust, speed, altitude). Figure 3-23 - Ground track of an A330 approach on runway 25L at Brussels Airport. Figure 3-24 - Example of a speed profile for an A330 non-CDO approach on Brussels Airport. Figure 3-25 - Example of an altitude profile for an A330 non-CDO approach on Brussels Airport. Figure 5-1 - All arrivals at EBBR (1 Jul. 2009 – 31 Oct.2011). Figure 5-2 - All arrivals at EBBR (%) (1 Jul. 2009 31 Oct.2011). Figure 5-3 - Participating airlines, arrivals on RWYs 25R/ (1 Jul. 2009- 31 Oct.2011). Figure 5-4 - Share of CDO-marked flights for the 5 participating airlines (arrivals RWY 25R/L). Figure 5-5 - Share of CDO-marked flights for Brussels Airlines (arrivals RWY 25R/L). Figure 5-6 - Share of CDO-marked flights for Jetairfly (arrivals RWY 25R/L). Figure 5-7 - Share of CDO-marked flights for Thomas Cook (arrivals RWY 25R/L). Figure 5-8 - Share of CDO-marked flights for DHL (arrivals RWY 25R/L). Figure 5-9 - Share of CDO-marked flights for Singapore Airlines Cargo (arrivals 25R/L). Figure 5-10 - Evolution of the number of CDO-marked arrivals. Figure 5-11 - Evolution of the percentage of CDO-marked arrivals. Figure 5-12 - Total amount of arrivals (participating airlines on RWY 25R/L; Oct.2011). Figure 5-13 - Number of CDO-marked arrivals per day (Oct.2011). Figure 5-14 - Percentage of CDO marked arrivals per day (Oct.2011). Figure 5-15 - Average amount of arrivals per hour (participating airlines on RWY 25R/L; Jan. -> Oct.2011). Figure 5-16 - Average amount of CDO-marked arrivals per hour (Jan. -> Oct.2011). Figure 5-17 - Average % of CDO-marked arrivals per hour (Jan. -> Oct.2011). Figure 5-18 - Average number of arrivals per weekday (participating airlines on RWY 25R/L; first 10 months of 2011). Figure 5-19 - Average number of CDO marked arrivals per weekday (participating airlines first 10 months of 2011). Figure 5-20 - Percentage of CDO marked arrivals per weekday (participating airlines first 10 months of 2011). Figure 5-21 - Average number of arrivals for RWYs 25R & 25L (participating airlines; first 10 months of 2011). Figure 5-22 - Average number of CDO marked arrivals for RWYs 25R & 25L – Phase 2 Version 4.2 - 15/02/2012- Page vii
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B3 SESAR JU PROJECT (participating airlines first 10 months of 2011). Figure 5-23 - Percentages of CDO marked arrivals for RWYs 25R & 25L (participating airlines first 10 months of 2011). Figure 5-24 - Cumulative distribution of flight levels for CDO-marked arrivals Figure 5-25 - Distribution of flight levels for CDO-marked arrivals (1 Jul.2009 -31 Oct.2011). Figure 5-26 - Evolution of the average FL at the moment arrivals are marked CDO. Figure 5-27 - Cumulative distribution of distance from touchdown after CDO-mark (1 Jul.2009 -31 Oct.2011). Figure 5-28 - Distribution of distance from touchdown after CDO-mark (1 Jul.2009 31 Oct.2011). Figure 5-29 - Evolution of the average distance from touchdown after CDO-approval. Figure 5-30 - Effect of switching to marking of flights on the CWP for flight levels . Figure 5-31 - Effect of switching to marking of flights on the CWP for distance from touchdown. Figure 5-32 - Parameters set in EFICAT to analyse radardata. Figure 5-33 - Examples for “No CDO”. Figure 5-34 - Examples for “CDO FL60”. Figure 5-35 - Example for “CDO FL80”. Figure 5-36 - Examples for “CDO FL100”. Figure 5-37 - CDO estimation by EFICAT, all arrivals, all runways. Figure 5-38 - CDO estimation by EFICAT, all arrivals, only runways 25R/L. Figure 5-39 - Comparison of CDO-performance estimated by EFICAT for marked flights from participating airlines and not marked flights for all airlines. Figure 5-40 - Comparison of CDO-performance estimated by EFICAT for marked flights from participating airlines with not marked flights for all airlines. Figure 5-41 - Comparison of CDO-performance estimated by EFICAT for Runways 25R and 25L. Figure 5-42 - EFICAT CDO estimation in absolute values – all runways, all arrivals with BEL-callsign. Figure 5-43 - Number of marked BEL-arrivals per aircraft type in the April-May 2011 dataset analysed with EFICAT. Figure 5-44 - CDO-performance per aircraft type estimated by EFICAT for Brussels Airlines arrivals on all runways. Figure 5-45 - CDO-performance per aircraft type estimated by EFICAT for Brussels Airlines arrivals on runways 25R and 25L. Figure 5-46 - Comparision of CDO-performance estimated by EFICAT for marked and not marked arrivals - per aircraft type for Brussels Airlines arrivals on runways 25R and 25L. – Phase 2 Version 4.2 - 15/02/2012- Page viii
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B3 SESAR JU PROJECT Figure 5-47 - Average absolute difference in EFICAT fuel estimation for marked and not marked flights – per aircraft type for all participating airlines. Figure 5-48 - Average absolute difference in EFICAT CO2 estimation for marked and not marked flights – per aircraft type for all participating airlines. Figure 5-49 - Average absolute difference in EFICAT fuel estimation for marked and not marked flights – per aircraft type for Brussels Airlines. Figure 5-50 - Average absolute difference in EFICAT CO2 estimation for marked and not marked flights – per aircraft type for Brussels Airlines. Figure 5-51 - Average percentage difference in EFICAT fuel estimation for marked and not marked flights – per aircraft type for Brussels Airlines. Figure 5-52 - Average percentage difference in EFICAT CO2 estimation for marked and not marked flights – per aircraft type for Brussels Airlines. Figure 5-53 - Difference of Eficat fuel estimation compared to FDM fuel data for Airbus 319. Figure 5-54 - Difference of Eficat fuel estimation compared to FDM fuel data for Airbus 330. Figure 4-13 - Airbus A330-300 – Early descent with several level-off parts. Figure 4-14 - Airbus A330-300 – Early descent with several level-off parts - Fuel Burn. Figure 4-15 - Airbus A330-300 – Early descent with several level-off parts - Fuel Burn low altitude. Figure 4-16 - Airbus A330-300 – Descent initiated slightly before the reference profile TOD. Figure 4-17 - Airbus A330-300 – Descent initiated slightly before the reference profile TOD - Fuel Burn. Figure 4-18 - Airbus A330-300 – Descent initiated slightly before the reference profile TOD - Fuel Burn low altitude. Figure 4-19 - Airbus A330-300 – Adherence to reference profile and speed schedule. Figure 4-20 - Airbus A330-300 – Adherence to reference profile and speed scheduleFuel Burn. Figure 4-21 - Airbus A330-300 – Descent above the reference profile. Figure 4-22 - Airbus A330-300 – Descent above the reference profile – Fuel Burn. Figure 4-23 - Airbus A330-300 – Descent above the reference profile – Fuel Burn Low Altitude. Figure 4-24 - Airbus A319 – FCOM Descent Profile. Figure 4-25 - Airbus A319 – FCOM versus FMGS profiles. Figure 4-26 - Airbus A319 – below profile. Figure 4-27 - Airbus 330 – below profile. Figure 4-28 - Airbus 319 – use of speedbrake profile. Figure 4-29 - Airbus 319 – high speed below 10.000ft profile. – Phase 2 Version 4.2 - 15/02/2012- Page ix
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B3 SESAR JU PROJECT Figure 4-30 - Airbus 319 – high speed below 10.000ft profile (2). Figure 4-31 - Airbus A330-300 arrival ref. A333_22: altitude and true air speed (TAS). Figure 4-32 - Airbus A330-300 arrival ref. A333_22: calculated CNT per engine. Figure 4-33 - Airbus A330-300 arrival ref. A333_22: LAmax noise contours of 60 (red line), 65 (orange line), 70 (blue line) and 75 (green line) dB(A). Figure 4-34 - Area of the LAmax noise contour of 60 dB(A) for the Airbus A330-300 analyzed flights. Figure 4-35 - Airbus A330-300 analyzed flights: LAmax noise contours of 60, 65, 70 and 75 dB(A). Figure 4-36 - A333_01 (NON MARKED, NO CDO (EFICAT)). Figure 4-37 - A333_06 (NON MARKED, CDO (EFICAT)). Figure 4-38 - A333_08 (NON MARKED, CDO (EFICAT)). Figure 4-39 - A333_22 (MARKED, NON CDO (EFICAT)). Figure 4-40 - Area of the LAmax noise contour of 50 dB(A) for the Airbus A319 analyzed flights. Figure 4-41 - Airbus A319 analyzed flights: LAmax noise contours of 50, 55, 60 and 65 dB(A). Figure 4-42 - A319_15 (MARKED, CDO (EFICAT)). Figure 4-43 - A319_16 (NON MARKED, NON CDO (EFICAT)). Figure 4-44 - A319_19 (MARKED, NON CDO (EFICAT). Figure 4-45 - A319_26 (NOT MARKED, CDO (EFICAT)). Figure 4-46 - Airbus A330-300 analyzed flights: LAmax noise profile under the flight track. Figure 4-47 - Airbus A330-300 analyzed flights: average LAmax noise difference in the zone 10 – 25 NM to landing compared to 3° - idl e thrust profile straight under the flight track. Figure 4-48 - Airbus A330-300 analyzed flights: LAmax noise profile 0.5 NM excentrical from the flight track. Figure 4-49 - Airbus A330-300 analyzed flights: average LAmax noise difference in the zone 10 – 25 NM to landing compared to 3° - idl e thrust profile at 0.5 NM excentrical from the flight track. Figure 4-50 - Airbus A319 analyzed flights: LAmax noise profile under the flight track. Figure 4-51 - Airbus A319 analyzed flights: average LAmax noise difference in the zone 10 – 25 NM to landing compared to 3° - idle th rust profile straight under the flight track. Figure 4-52 - Airbus A319 analyzed flights: LAmax noise profile 0.5 NM excentrical from the flight track. Figure 4-53 - Airbus A319 analyzed flights: average LAmax noise difference in the zone 10 – 25 NM to landing compared to 3° - idle th rust profile at 0.5 NM excentrical from the flight track. – Phase 2 Version 4.2 - 15/02/2012- Page x
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B3 SESAR JU PROJECT Figure 4-54 - Visualization of ground tracks on runway 25R. Figure 4-55 - Visualization of ground tracks on runway 25L. Figure 6-1 - Point Merge System for Arrivals RWY25 Left.
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LIST OF TABLES Table 3-1 – Example - Main fields for Marked CDO-flights extracted from Eurocat log files. .31 Table 3-2 - Use of recorded data items. ...............................................................................49 Table 4-1 - Airbus A319 – Overview of all flights – Fuel Burn. ............................................125 Table 4-2 - Airbus A319 – Overview of all flights with CDO-approval – Fuel Burn. .............125 Table 4-3 - Airbus A319 – Overview of all flights without CDO-approval - Fuel Burn. .........125 Table 4-4 - Airbus A333 – Overview of all flights - Fuel Burn. .............................................126 Table 4-5 - Airbus A333 – Overview of all flights without CDO-approval - Fuel Burn. .........127 Table 4-6 - Airbus A333 – Overview of all flights without CDO-approval – Fuel Burn. ........127 Table 4-7 - Overview of all analyzed flights - Airbus A319. .................................................129 Table 4-8 - Overview of all analyzed flights with CDO-approval - Airbus A319. ..................130 Table 4-9 - Overview of all analyzed flights without CDO-approval - Airbus A319. .............131 Table 4-10 - Overview of all analyzed flights - Airbus A333. ...............................................132 Table 4-11 - Overview of all analyzed flights with CDO-approval - Airbus A333. ................133 Table 4-12 - Overview of all analyzed flights without CDO-approval - Airbus A319. ...........134 Table 0-1 - Flight Phases - Airbus FMS. .............................................................................177 Table 0-2 - Descent profiles - Airbus A320. ........................................................................190 Table 0-3 - Descent profiles - Airbus A330. ........................................................................190 Table 0-4 - Impact of anti-ice and temperature - Airbus A320. ............................................191 Table 0-5 - Impact of anti-ice and temperature - Airbus A330. ............................................191
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B3 SESAR JU PROJECT
EX ECUTIVE SUMMARY
The B3-projectwas performed by a consortium, consisting of an airline (Brussels Airlines), an air navigation service provider (Belgocontrol) and an airport operator (The Brussels Airport Company). Besides the B3parners also Jetairfly, Thomas Cook, DHL, Singapore Airlines Cargo participated in the CDO-trials. This project was conducted within the scope of the AIRE-initiative (Atlantic Interoperability Initiative to Reduce Emissions), managed and financed in Europe by the SESAR Joint Undertaken. The B3-project aimed to perform and evaluate partial continuous descent flight trials in a complex radar vectoring environment.Main objectives of the trials were to test the operational concept and to quantify the fuel, CO2 and noise benefits, and this in a close cooperation ofthe three B3 partners. The applied concept is that approach controllers continue to radar-vector the approaching aircraft to the ILS-interception (no change), regularly provide an estimated of the remaining distance to touchdown (lateral guidance); and allow the aircraft to descend continuously when the traffic situation allows for it (vertical liberty).Appropriate consecutive descent levels are given to ensure vertical separation and to keep the aircraft in controlled airspace. The pilot will then optimize the approachin order to descend via a continuous vertical profile and using minimum engine thrust.The trials were performed for approaches into Brussels Airport, starting below FL150. The CDO-trials in the context of the B3-project were performed and analysed for a period of 10 months, starting January 1st, 2011and until October 30th, 2011.During this period, for not less than 3.094 flightsCDO was activily facilitated. The B3-project demonstrated that for Airbus 319 aircraft, an average 50 kg of fuel and 160 kg of CO2 was gained for CDO-facilitated flights below FL150, compared to not-CDO-facilitated flights.For Airbus A330-300 aircraft, the average amount of fuel saved was 100 kg, corresponding to 315 kg of CO2on similar descents. The project was able to demonstrate
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B3 SESAR JU PROJECT that, even in an operating environment not really suited for the conduct of CDO, substantial gains could be achieved. In order to study possible noise effects associated with CDO facilitation, noise modeling starting from operational flight data was performed. Significant gains on the noise impact on the ground in the distance range between 10 and 25 nautical miles from touchdown are obtained: in this area (before ILS-capture) the maximum noise level (LAmax) shows an average reduction of 2 dB(A) for Airbus 319 and 3 dB(A) for Airbus 333 between CDO-facilitated and not-CDO-facilitated flights. The main issues that needed to be solved in the project were the fact that optimum performance not only depends on aircraft type but also on airline policy, actual aircraft weight, temperature and wind and starting position and therefore are only known on board of the aircraft and not by the controlling Air Traffic Controllers. As known from the start of the project, CDO is only possible in conditions with low traffic, arriving well separated in time and space, this in order to allow the pilot to optimize the vertical approach path while ATC can guaranteethe required separation between individual aircraft.The trial showed that for about 9% of the approaches performed bythe participating airlines, a CDO was facilitated. The trials proved to be successful and the aim is to firmly implement the trialled operational concept, always taking into account that it will remain only possible when the traffic allows for it. Although an ICAO CDO-manual is available since 2010, there still remains work to be done for international standardisation of the facilitation of CDO in a radar vectoring environment. Awaiting this standardisation, it is important to be clear and concise in the development and publication of local CDO procedures.
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B3 SESAR JU PROJECT 1.
FOR EWORD
1.1
ABOUT THE DOCUMENT
This document provides a detailed description of the activities, proceedings and results of the Phase 2 of the B3-project, conducted within the scope of the AIRE-initiative (AtlanticInteroperability Initiative to Reduce Emissions), managed and financed in Europe by the SESAR Joint Undertaken. The reader is invited to consult the Phase 1 Report of the same project in order to better understand the context, obectives and project organization.
1.2
THE AUTHORS
This document has been developed and compiled as a joint effort by key project representatives of the three involved partners in this project.
1.3
STRUCTURE OF THE DOCUMENT DOCUMENT
This document has been structured as follows: Executive Summary - gives a management overview of the content and main issues of thestrategy. Foreword - describes the purpose of the document, its authors and its structure. Introduction – provides an introduction to the project and the report. Description of the solution - provides the context necessary in order to understand the project, its challenges and its objectives. Data collection process - describes the process, the used tools and the various analysis activities performed throughout the project. Data analysis results – lists and discusses the detailed results of the various analysis, and provides the overall results and conclusions. Annexes - provide additional background information.
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B3 SESAR JU PROJECT 1.4
APR: ATA: ATCo: CAS: CCO: CDO: CWP: DGE: EFICAT: FDM: FL: FMC: FMGS: GIS: HPFC: IAS: INM: LRC: MRC: ND: NM: NMS: PFD: SAS: STAR: TAS: VPFC:
GLOSSARY
Automatic Position Report Actual Time of Arrival Air Traffic Controller Calibrated Air Speed Continuous Climb Operations Continuous Descent Operations Controller Working Position Directorate General Equipment Eurocontrol Flight Information Consistency Analysis Tool Flight Data Monitoring Flight Level Flight Management Computer Flight Management Guidance System Geographical Information System Horizontal Projected Flight Curve Indicated Air Speed Integrated Noise Model Long Range Cruise Maximum Range Cruise Navigation Display Nautical Miles Noise Monitoring system Primary Flight Display Statistical Analysis Software Standard Arrival Route True Air Speed Vertical Projected Flight Curve
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B3 SESAR JU PROJECT 2.
INTRODUCTION
The B3 project aimed to perform and analyse partial continuous descent flight trials in a complex radar vectoring environment. The B3 consortium was built with an airline (Brussels Airlines), an ANSP (Belgocontrol) and an airport operator (The Brussels Airport Company), all bringing their own expertice, data and tools into the project. Besides the B3-partners other airlines participating in the CDOtrials are Jetairfly, Thomas Cook, DHL, and Singapore Airlines Cargo. The trials are performed for arrivals to EBBR in one of the most complex airspaces of Europe. Therefore, rather than to trial CDOs from top of descent for a few individual flights, the operational concept of the B3-project aimed to improve the CDO quality for an as large as possible number of flights in the approach part of the descent. In total 3094 CDO trials were performed in a period of 10 months starting from 1/1/2011 until 30/10/2011. The main objectives of the trials were to test and optimize the operational concept and to quantify the fuel, CO2 and noise benefits. These objectives were obtained through a constructive and open collaboration between the partners and an extensive deployment of data and tools. Developments were made to generate a database with CDO-approved flights, a beta version of the Eurocontrol EFICAT CDO-analysis tool was tested, FDM-data were extracted and analysed and a method was developed to feed the INM-tool with FDM-data to calculate the noise impact. Also in the course of the project information on marked flights was exchanged continuously among the different partners. Through this report, the B3-team is happy to share its results with the wider aviation community.
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B3 SESAR JU PROJECT 3.
DESCRIPTION OF TH E PROOF - OF - CONCEPT
S O LUTION
3.1
DESCRIPTION AND PROOF PROOF OF CONCEPT
TO
LEAD
TO
THE
In this section we briefly provide the basic principles governing the descent phase of flights performed by modern jet transport aircraft. For a more comprehensive description of descent operations, we invite the reader to consult the Appendixes to this report. 3.1.1
VERTICAL FLIGHT PROFILE PROFILE – TYPICAL
A typical flight profile consists of: 1. A lateral profile 2. A vertical profile In our B3 concept, we focussed on the vertical profileof thedescent phase of the flight.
Figure 3-1 - Typical vertical profile The descent phase starts at the top-of-descent (TOD) point, which is typically less than 200NM from destination. Generally, the engine thrust will be set to idle. Initially, the rate-of descent will be adjusted to achieve a descent Mach; below the crossover altitude, in an – Phase 2 Version 4.2 - 15/02/2012 - Page 4
B3 SESAR JU PROJECT unconstrained situation, the rate-of-descent will be adjusted to adhere to a descent IAS. Airspace constraints may limit the selected speed, typically below a designated altitude and/or at a waypoint. Ideally, no intermediate level-off is desired (implicit Continuous Descent Operation – CDO). The approach phase starts when the approach deceleration point is passed. The deceleration point is computed backwards from the landing point based on optimized flap/slat configuration changes, altitude/speed constraints and flight path. For each phase of flight, the aircraft operator may define/calculate an “ideal” speed. Application of all these “ideal” speeds will result in an “ideal” flight profile for the aircraft operator. The “ideal” profile is intended to achieve an optimization of the direct operating cost for a given flight. It may be observed that an operator may deviate from its own “ideal” profile in order to cope with other specific operating/economic conditions. Many parameters do influence the calculated speeds. Hence, even for the same aircraft operator on the same type of aircraft, these speeds may be different for each flight (e.g. due to a different mass of the aircraft)! It should be emphasized that the “ideal” profile will NOT necessarily result in the optimum fuel usage! Generally, a trade-off is made between the fuel-related cost (CF) and the timerelated cost (CT). The ratio between both cost factors is commonly called the Cost Index(CI).
CI =
C Time C Fuel
The Cost Index is an airline depending variable introduced in the Flight Management Computer (FMC) to optimize performance calculations including Mach and step climb optimization. The cost index effectively provides a flexible tool to control fuel burn and trip time.Knowledge of the airline cost structure and operating priorities is essential when aiming to optimize cost by trading increased trip fuel for reduced trip time or vice-versa. As a result, application of different cost index values will lead to different locations for the topof-climb and top-of-descent points, and fuel burn in the various phases of flight will differ as well. However, note that an operator will strive towards the most economical solution from gate-to-gate which means that he is not primarily interested in the individual figures for each flight phase. ‘Flight efficiency’ may be seen as the degree to which the actually flown flight profile will adhere to the ‘ideally’ planned profile. Each deviation from this profile (theoretically, at least!) will result in a cost penalty.
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B3 SESAR JU PROJECT Once a value for the cost index has been determined by the operator for execution of one or moreflights, the resulting profile may be called the “airspace user’s preferred trajectory”. This is the starting point for the “business trajectory” philosophy as used by SESAR. The “solution” proposed in the B3-project consisted in applying partial CDO’s to the maximum extent possible, allowing the aircraft operator to fly as close as possible to its preferred vertical trajectory during a large part of the descent phaseof flight in a dense and complex radar-vectoring environment. The “data collection process” was aimed at finding out how successful this could be done: how well could the “airspace user’s preferred trajectory” be achieved/approached in the descent phase of flight?
3.1.2
DESCENT – GENERAL PRINCIPLES
Descending a (transport) aircraft from its cruising level down to the landing runway of the destination airport is a matter of “energy sharing”. For commercial jet operations, a so-called “Mach/CAS Descent” is usually flown. Mach/CAS descents employ a descent speed profile characterized by a constant Mach segment (above the ‘crossover altitude’ – ca. FL290) followed by a constant calibrated airspeed (CAS)1 segment, performed at idle thrust for maximum fuel efficiency. Mach/CAS descent schedules are typically described in aircraft operating manuals. The Mach/CAS speeds are adjusted to yield optimum fuel efficiency, time efficiency, or (usually) a combination of the two. Airline policies may recommend selected Mach/CAS schedules to suit their specific operational and economic conditions. Below FL100, the ‘ideal’ descent profile may be ‘spoiled’ by altitude/speed constraints imposed by the flown STAR2 and/or terminal airspace regulations. Ideally, no intermediate level off between top-of-descent and capture of the glide path signal is planned: a Continuous Descent Operation (CDO) at a defined speed, performed in idle thrustconditions is the preferred option.
1 2
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B3 SESAR JU PROJECT
Figure 3-2 - Simplified descent profile. Figure 3-2shows a simplified descent profile with various Mach/CAS followed by a standard IAS to final. The location of the Top-Of-Descent (TOD) point is calculated, taking into account: o The preferred Mach/CAS speed schedule. o The predicted wind profile between cruise altitude and ground level at the destination airport. o The estimated landing mass of the aircraft. o Deceleration distance to comply with airspace constraints (i.e. max. 250kt IAS below FL100). o Final approach deceleration distance. Note that the descent is performed at idle thrust. Adverse weather conditions may impose a higher than normal idle thrust setting, resulting in a more distant TOD location
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B3 SESAR JU PROJECT 3.1.3
IMPACT OF NONNON-ADHERENCE TO THE CALCULATED DESCENT PROFILE
The location of the TOD-point is highly dependent (amongst other parameters) of the desired speed at which the descent is expected to be flown. The desired speed most likely will be the result of a cost calculation, using the appropriate cost index value for the aircraft operator and the subject flight.
Figure 3-3 - Location of the "Top-of-Descent" The ‘optimum’ or ‘ideal’ descent can only be achieved when an unconstrained descent may be flown, starting at the calculated top-of-descent, flying at the preferred speed (indicated as “ECON-speed in Figure 3-3), down to the landing runway. As soon as deviations against this descent path happen, cost penaltieswill occur: 1. Descents performed ‘below’ the intended descent path will result in a time penalty if flown at idle thrust. If thrust is used in such a descent, either during – Phase 2 Version 4.2 - 15/02/2012 - Page 8
B3 SESAR JU PROJECT a level-off portion and/or in order to maintain the desired speed, more fuel than anticipated will be burned. This situation may happen when the flight is requested to descent before having reached the optimum TOD-point. 2. Descents performed ‘above’ the intended descent path will inevitably result in a fuel penalty due to the fuel burned during the extra level segment(s), executed either at cruise altitude, or at any other intermediate altitude. This situation will occur when the flight is requested to maintain the cruise altitude beyond the optimum TOD-point. It is important to realize that the incurred penalty is not related to the descent phase of the flight, but to the direct operating cost of the entire flight. Looking at the descent phase of the flight only, may lead to erroneous conclusions!
Figure 3-4 - TOD penalties. We notice that the higher the cost index: the steeper the descent path (the higher the speed); the shorter the descent distance,the later the top of descent (TOD) point. As for the climb, descent performance is a function of the cost index; indeed, the higher the cost index, the higher the descent speed. But contrary to the climb, the aircraft gross weight and the TOD flight level appear to have a negligible effect on the descent speedcomputation. – Phase 2 Version 4.2 - 15/02/2012 - Page 9
B3 SESAR JU PROJECT Values for time, distance, Mach/CAS, fuel consumption do vary much with flight conditions such asTOD flight level temperature and wind, but are less variable with respect to gross weight. Similar to the climb, delta values with regard to time and distance are largely the same whatever the initial flight conditions. In addition, usually, the wind model accounted for by the FMS in its speed/Mach calculationresults: from current position up to 150 NM ahead: actual encountered wind, further up, a wind evolving linearly towards the wind inserted by the pilot into the FMS at that flight level. The nominal flight path (i.e. TOD-point) should not be affected if the wind-corrected speed/Mach is applied. 3.1.4
IMPACT ON FUELFUEL-BURN OF A PARTIAL CDO CDO - PROFILE
The optimum solution for descent consists in the execution of a continuous descent in idle thrust at the desired speed. Figure 3-5shows a typical (optimum) descent profile and fuel burn figures for the Airbus A330-300. Any change to this descent profile will result, as seen in the previous section, in a cost and/or fuelpenalty. The fuel burn line represents the optimum achievable for descent.
Figure 3-5 - Airbus A330-300 – M.80/300KT/250KT descent profile and fuel burn.
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B3 SESAR JU PROJECT The trial aimed to evaluate the gains obtained by flying part of the descent profile in CDOmode. TheCDO-part typically began at altitudes between FL60 and FL150. When the CDOclearance is issued (see Figure 3-6), the subject aircraft was either: 1) Below the intended descent profile: The aircraft started to descend too early, or descended at higher descent rate than anticipated. Most likely, a level portion of flight was executed below cruise level, resulting in some extra fuel burn. If not, a portion of the descent was flown in idle at a lower speed, resulting in a time penalty. 2) On the intended descent profile: Either the aircraft performed an ‘ideal’ descent, or found itself on the ideal descent path after a portion of level flight. Therefore, even in this case, a fuel penalty versus the optimum descent path cannot be excluded. 3) Above the intended descent profile: The aircraft started too late its descent, or found itself above the ideal descent path after a portion of level flight. Clearly, more fuel than anticipated was burned or more time was spent than anticipated. Clearly, possible gains in fuel burn achieved through the execution of a partial CDO, was biased by extra fuel burn or extra flight time, achieved earlier in the descent phase of flight. Stated differently, the overall fuel burn figure of the flight was dependent of the flown profile before issuance of the CDO clearance.
Figure 3-6 - Initiation of a CDO at or below FL150. If a continuous descent is initiated at FL150 or below, it is clear that the fuel burn during that phase of flight will be proportional to its duration. The shortest duration will be achieved by – Phase 2 Version 4.2 - 15/02/2012 - Page 11
B3 SESAR JU PROJECT aircraft, which are at high speed above their ideal descent path when the CDO-clearance is issued, because they will have to descent faster. Hence their fuel burn will seem optimal, when compared to flights on or below the ideal profile
Figure 3-7 - Example of descent profile and fuel burn below FL150 - Airbus A330-300. Figure 3-7shows a typical descent profile flown by an Airbus A330-300 aircraft below FL150. The vertical profile is shown by the dark blue line, while the thin purple line shows the FCOMsuggested profile. The magenta illustrates the throttle activity: virtually ‘idle’ during the whole descent until capture of the glideslope below 3.000 ft. This results in a fuel burn figure (cyan line), which is significantly better than the fuel burn figure given by the FCOM (yellow line). The difference is explained by the fact that the aircraft was flying much faster than normal, resulting in a shorter duration of this phase of flight, and a corresponding fuel “saving” versus the standard. The fact that the aircraft was above its profile at high speed, however, indicated that most likely, extra fuel was burned in the flight phases before passing FL150 in descent. This simple example clearly demonstrates that monitoring of the fuel burn during the CDOportion could obviously lead to wrong conclusions in many cases. Therefore, in the B3project,we monitored the fuel burn from TOD until GS-interception. As a consequence however, it was virtually impossible to establish one (or more) baselines. In this project, comparisons were made between declared CDO-flights and other flights, based on an initial assessment of the descent profiles, starting at TOD. Assessment of the profiles was done using the Eurocontrol Eficat-tool; detailed analysis of the fuel burn figures and engine throttle ‘activity’ relied on FOQA-data of the subject flights.
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B3 SESAR JU PROJECT 3.1.5
KNOWLEDGE OF DESCENT PATH BY THE ANSP
For the application of CDOs as intended in this program, ATS needed to acquire knowledge about what may be “expected” or is “feasible” for (at least) each aircraft type participating in the CDO-trials. The next figure shows, for a given aircraft type, a “nominal” descent profile and the extreme cases, taking into consideration possible variations of all parameters which have an impact on the overall descent profile.
Figure 3-8 - Different descent profiles. The ‘extreme’ cases define the window or “entry gate” in which the aircraft are expected to arrive, when performing its preferred (or ‘ideal’) descent. In the shown example, the “entry gate” at FL100 is situated between 27 and 45 NM before touchdown. The subject aircraft will need to be at FL100 in descent in order to be able to execute the remaining part of the descent at its preferred speed. Ideally, for the purpose of definition of the “entry gate” at various altitudes, descent profile data (speed, time, fuel, distance to touchdown [or xxx ft] at several altitudes) were to be obtained for (not exhaustive list):
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B3 SESAR JU PROJECT • “Light” aircraft – Cost index 0. • “Heavy” aircraft – Cost index 0. • “Light” aircraft – High cost index. • “Heavy” aircraft – High cost index. • Same profiles for high and low temperature? • Same profiles for 50kt headwind/tailwind. • ??? Unfortunately, Brussels Airlines did not have the means to calculate the required data for the participating aircraft types. A simplified method was used instead. For each aircraft type participating to the trial, a survey of descent profile data, as published in the Flight Crew Operating Handbook, was made. In addition, the descent profile as provided by the Eurocontrol developed BADA-model, was reviewed as well. Figure 3-9shows the descent profiles below FL150 for the Airbus A330-300 aircraft. The 3 and 4degrees slopes are added as a reference.
Figure 3-9 - Descent profiles below FL150 for A330-300. Analysis of all descent profiles revealed that a 4-degree descent path was flyable for all medium weight (M) category aircraft, while a 3-degree descent path was seen as the limit for a heavy-weight (H) category aircraft.
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B3 SESAR JU PROJECT
Figure 3-10 - Difference 3 to 4° glide path.
The 3 and 4-degree rule was used by the Air Traffic Controllers to assess the feasibility and to plan the issuance of a CDO-clearance. The descending aircraft needed to be located either on/below the 3-degree (H), resp. the 4degree (M), slope in order to be eligible for a CDO-clearance. When located above, the Air Traffic Controller inevitably needed to cater for extra track miles in the pattern for allowing a workable descent and approach solution. Obviously, this last scenario needed to be avoided as much as possible.
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B3 SESAR JU PROJECT 3.2
ACHIEVEMENT OF THE PROJECT
In one of the most congested airspace in Europe, the consortium B3 (Belgocontrol, Brussels airport and Brussels Airlines) proposed a challenging integrated approach to optimise the descent within the approach sector. The main objective was and is to reduce CO2 emissions by contributing to the introduction in Europe of a fairly new concept in aviation: Continuous Descent Approaches (CDO). The idea was to validate the proposed project and demonstrate the environmental benefits of the CDO-concept after implementation flight trials performed during 2010-2011. The principle of Continuous Descent Operation (CDO) is an approach procedure that allows descending on an optimum basis. The Continuous Descent Operation (CDO) involves the management of the aircraft configuration (flaps, speed brakes, landing gear, and thrust) by the pilot (known as descent energy management) to use the minimum required thrust on a variable glide angle into an airport. By using the lowest thrust possible and averaging a standard 3-degree glide angle at lower level, aircraft will burn less fuel, emit less CO2 and produce lower levels of noise than aircraft using higher thrust settings as in a “step down” method approach. For stabilization reasons a short level segment before interception of the ILS can be done (as proposed by the FMGS), also in a CDO.
Figure 3-11 - Descent optimization.
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B3 SESAR JU PROJECT Area in which the aircraft adjusts its flight path for the final approach
CDO approach Standard approach
Standard configuration change
Figure 3-12 - CDO approach. Figure 3-12is a depiction of the 3-degree and step down approaches. 3.2.1
THE CDO CHALLENGE
For many airports, the opportunity to implement a CDO is limited because of the volume of air traffic on approach and in the vicinity of the airport especially during daytime periods. When approaching traffic is heavy, a pilot may need to adjust thrust, flap settings, and extend landing gear to maintain safe and consistent spacing with other aircraft in the terminal area. Extending flaps, and landing gear makes an aircraft “dirty” (i.e., increases drag), which requires the application of additional thrust to keep the aircraft flying at the same speed. During a continuous descent approach with engines running at idle power, from cruise altitude or from an intermediate level until the final stage of the approach. With this in mind, cooperation between airlines, airports and ANSPs (B3 Consortium) is focused on the validation of 3-Dimensional (3D) performance-based operations. The 3D being • •
Lateral (X &Y positions, responsibility of the ANSP (Belgocontrol)) Vertical (Z position, responsibility of the pilot (Brussels Airlines) within the margins allowed by ATC
The B3 project focused on operations that were feasible with current technology with an attention on the last part of the descent, where the flight is under control of the Belgocontrol Approach unit.
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B3 SESAR JU PROJECT 3.2.2
EUROCONTROL APPROACH TO CDO
“Continuous Descent Operation is an aircraft operating technique in which an arriving aircraft descends from an optimal position with minimum thrust and avoids level flight to the extent permitted by the safe operation of the aircraft and compliance with published procedures and ATC instructions.” Some basics though must be kept as main goals: 1. A CDO uses descent profiles that reduce noise, fuel burn and CO2 emissions 2. Ideally, a CDO starts from the Top of Descent, but a CDO can also start at a lower level. 3. The avoidance of level flight (continuously descending) is more important at lower altitudes where noise becomes more significant. At higher altitudes, level flight at minimum thrust to reduce speed may in some cases help to reduce fuel burn and facilitate better CDO performance at lower altitudes where speed control becomes important for CDO achievement. 4. Low Drag configuration should be maintained to the maximum extent possible.
3.2.3
OBJECTIVES OF THE B3 PROJECT
1. For the trial period, a CDO was only to be expected in lower levels. In the deployment phase, the feasibility to increase the altitude of the entry gates was assessed. All must be well aware that at lower levels, the standard descent in clean configuration and idle thrust will be around a 3° glide (5%) whereas at higher level t he glide angle will be steeper, this is mainly aircraft related. The procedure was based on radar vectoring for an optimum route. As the pilot is unaware of the route that the controller would issue him, he received additional information. During the descent the controller provided the remaining distance to go and thus permit the pilot/aircraft to compute his position in relationship with the ideal CDO profile. The controller explicitly approved a continuous descent. The continuous approach is a team effort from the controller and the pilot. • The controller was responsible for issuing radar vectors to the aircraft (giving headings and the distance to go) and for all traffic separation • The pilot was responsible for the descent profile, ensuring he remained as close as possible to his ideal continuous descent profile. When cleared for a CDO, the pilot expected that the controller would anticipate descent clearance to avoid any level off. – Phase 2 Version 4.2 - 15/02/2012 - Page 18
B3 SESAR JU PROJECT 2. As a prerequisite, the CDO trials were performed: • Without compromising safety, • Without bringing the capacity below what is needed to accommodate traffic demand. • Without adverse effect on punctuality
3.2.4
REFERENCE FOR CDO AT EBBR (BELGOCONTROL & BRUSSELS AIRLINES)
3.2.4.1
GENERAL
For the Trial period the following conditions were applied • Tailwind component lower than 5 kt (gusts incl) • no adverse weather conditions that may affect the approach (wind shear, thunderstorms, etc.) This differed from the current AIP (ref. EBBR, AD2.21) conditions which are more restrictive, namely: 3.4 NOISE ABATEMENT APPROACH AND LANDING PROCEDURES Noise abatement descent and approach procedures using continuous descent and reduced power / reduced drag techniques should be used when following conditions apply: ILS available runway clear and dry visibility exceeding 1 900 m ceiling higher than 500 ft above AD ELEV cross wind component lower than 15 kt (gusts incl) tailwind component lower than 5 kt (gusts incl) no adverse weather conditions that may affect the approach (wind shear, thunderstorms, etc.) Turbo-jet powered aircraft shall use as final flap setting the minimum certified landing flaps setting published in the Aircraft Flight Manual for the applicable conditions. However, each pilot-in-command may use a different flaps setting approved for the aircraft if he determines that it is necessary in the interest of safety.
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B3 SESAR JU PROJECT Other AIP-provisions Other AIP-provisions and more specifically AD2.21 Noise Abatement Procedures, point 3. Arrival Procedures and AD2.22 Flight Procedures, point 2. IFR flights (inbound) remain unchanged. Scope of the tests The tests was performed on runways 25L & 25R The zone of the tests was limited to EBBR-TMA + CTA East. The tests were only open for airlines that formally participate and that confirm that all the pilots flying under their flag are briefed. There is no limitation in time of day for the tests. However tests were only to be expected in low traffic situations and on ATCO’s discretions The only impacted ATC-unit is CANAC/APP. Typical phraseology
Circumstances Continuous Approval
Typical Phraseology
Descent
[aircraft call sign], [WHEN READY] DESCEND [INITIALLY] TO (level), QNH (number) [units], (distance) FROM TOUCHDOWN,CONTINUOUS DESCENT APPROVED
Acknowledgment
* DESCEND TO (level), QNH (number) [units][aircraft call sign]
Non-acceptance **
*DESCEND TO (LEVEL), QNH (number) [units] NEGATIVE CONTINUOUS DESCENT [aircraft call sign]
Cancellation
[aircraft call sign] STOP DESCENT AT (level)
Cancellation back
Read *STOP DESCENT AT (level) [aircraft call sign]
* denotes pilot transmission ** only during test-period – Phase 2 Version 4.2 - 15/02/2012 - Page 20
B3 SESAR JU PROJECT [ ] Words in square parentheses indicate optional additional words or information. Example for intermediate level “BEL1721, heading 300, descend INITIALLY to 4000 ft, QNH 1018, 30 NM from touchdown, continuous descent approved” Next “BEL1721, descend to 3000 ft, cleared ILS 25L” If feasible, followed by an updated distance from touchdown Example with use of “when ready” e.g.for approaches via Kerky – BUN and level at FL80/FL90. “BEL1721, WHEN READY descend to 3000 ft QNH 1018, 45 NM from touchdown, continuous descent approved” 3.2.4.2
BELGOCONTROL
Belgocontrol is the Belgian Air Navigation Service provider and is charged with the following tasks of public service: -
-
Assure the safety of air traffic control in the airspace for which the Belgian state is responsible Assure at Brussels Airport the control of the aircraft movements in approach, on landing, on the runways and the taxiways, as well as the guidance of aircraft on the platforms.Belgocontrol assures also the safety of air traffic on the regional public airports and airfields. Deliver information on the aircraft, their control, their movements and the noticeable effects of these.
Operational concept for the CDO-trials: APP-controllers did radar-vector aircraft to the ILS-interception, regularly providing distance from touchdown information and explicit approving the aircraft to descend continuously. Intermediate levels were used when needed for traffic separation or for keeping the aircraft in controlled airspace. Controllers identified flights eligible for CDO based on the airline company (callsign).
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B3 SESAR JU PROJECT 3.2.4.3
BRUSSELS AIRLINES
During these lower level transitions the aircraft had to reduce its speed and start its initial configuration. The pilots were challenged to continuously recompute energy level versus distance to land, while adhering to published speeds. In optimal conditions, each pilot can fly a smooth transition from high cruising speed to final approach speed. This implicates that pilots should, to the max extent possible, keep their aircraft in clean configuration and idle thrust, keeping in mind that aircraft must be stabilized on approach in landing configuration at latest 1.000ft or 500ft depending on company regulations. This technique is mostly referred to as low drag/low noise technique. This reduces the noise level. Noise abatement descend and approach procedures using continuous descent and reduced power / reduced drag techniques should only be accepted when following conditions apply:
To achieve this in the safest way, some limitations were applied until both pilots and controllers get more familiar with the concept CDO - Low Noise Approaches • •
tail wind component lower than 5 kt (gusts included) no adverse weather conditions that may affect the approach (wind shear, thunderstorms, etc.)
Turbo-jet powered aircraft should use as final flap setting the minimum certified landing flaps setting published in the Aircraft Flight Manual for the applicable conditions or their company SOP configuration. However, each pilot-in-command may use a different flaps setting approved for the aircraft if he determines that it is necessary in the interest of safety.
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B3 SESAR JU PROJECT 3.3
THE FLIGHT TRIAL PERIOD PERIOD
3.3.1
PHASE ONE
During the phase one (21/09/2010 till 21/01/2010), pilots and controllers were briefed by their appropriate authorities. The initial procedure has already been examined by the BSA (Belgian Security Agency) and has received a formal approval. The procedure being authorized, pilots and controllers had already received initial briefings. In view of this positive evolution, some very limited trial flights have taken place but the data retrieved for proper analysis are very limited. Final briefings have been produced and forwarded to all participants. • •
All ATCO’s have been briefed for the 15th of December All Brussels Airlines pilots have been briefed for the 1st of December
To be able to assess in an objective way the gain in fuel burn, CO2 emissions reduction and possible noise impact, Brussels Airlines set up a program to track down specific flight data. Belgocontrol developed a means for controllers to simplify the marking of CDO-approved flights (see chapter on data collection process and tools) and Brussels Airport with subcontractor KU Leuven explored INM-possibilities for noise assessment (see chapter on data collection process and tools).Also during phase one the development of an analysis method based on these flight data (trial and non-flight trial data) was started. Phase one has brought the key players on the same wavelength. Operational live flight tests that are already on-going will continue during Phase two, also ‘the quick performance scan’ will continue.
3.3.2
PHASE TWO
The phase two has run from January 21st till December 21st 2011. During phase two, flights trials and analysis have run together until June1st 2011. In January 2011 until June 2011 the validation exercise was finalized and the final report started to be detailed. This has required frequent information inside the B3 Consortium: monthly meetings have been held to exchange points of view and to adapt procedures as required. Flight data was exchanged for flights from October 2010 until October 2011. During Phase 2, from January 2011 until October 2011, not less than 3.094 arriving flights were granted a CDO-descent. Detailed analysis was performed on 56 randomly selected Airbus-flights.
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B3 SESAR JU PROJECT The project didn’t require any change in ground or airborne equipment. Any ATC can implement the project; any airline can fly the CDO. So the validation depended mostly on two factors: 1. Ability to optimise the number of CDOs while maintaining safe separation between flights. Controllers have always assured a safe separation between aircraft.Some factors influencing the possibility to approve a CDO were: the number of flights that are simultaneously approaching, their relative position, direction of the individual aircraft movement, altitudes and speeds.Speed control remained a last resort, as this caused erratic CDOs. 2. Ability for pilots to correctly compute a continuous descent in respect of the applicable local procedures (250kts below 10.000ft, established on ILS latest at 3.000ft at night/ 2.000ft during daytime). Speed reduction was done in a smooth continuous way to avoid level flight although a segment of 2.5 NM level flight is still considered as CDO. 3.3.2.1
TRANSITION INTO OPERATIONS
After the trial period, a formal evaluation has been organized to assess the need for further adaptation or the possibilities for implementation. As previously mentioned, no need for ground or aircraft equipment changes has beenidentified, rendering the implementation dependent on operational elements as well as on the conclusion on the benefits on CDO.
3.3.2.2
PACE OF CHANGE
It is expected that the simplicity of this working method should allow all airlines to jump into the procedure without any internal procedure publication requirement. In case of a general publication into the AIS (Aeronautical information system), the workgroup intends to continue to function during 3 months in order to tackle any undetected problem. Every implementation proposed by B3 has been subject to a formal approval from the BSA (Belgian Supervising Authority).
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B3 SESAR JU PROJECT 4.
DATA COLLECTION PROC ESS, TOOLS AND ANALY SIS
4.1
OVERVIEW
An overview of the Data Collection Process, Tools and Analysis performed is given in figure on the next page. Data sources are indicated as cylindrical containers Data analysis steps are shown as rectangles with full lines.Where applicable, he tool used for the analysis is included in the rectangle. Supporting steps are indicated as dotted rectangles. The line colour of the containers and rectangles is a reference to the B3-partner that is originator for the data or performs the analysis action. The fill colour of the containers and rectangles groups related processes. This is all illustrated in the legend below (Figure 4-1).
Figure 4-1 - Data Collection scheme legend.
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B3 SESAR JU PROJECT
Figure 4-2 - Data Collection scheme. – Phase 2 Version 4.2 - 15/02/2012 - Page 26
B3 SESAR JU PROJECT 4.2
DATA SOURCES SOURCES
4.2.1
NMS (NOISE MONITORING SYSTEM) SYSTEM)
Two sources of radar data are used. One of the sources is the NMS (Noise Monitoring System) from Brussels Airport in which radar data are stored in a database in conjunction with flight data and measured noise values.This data source is limited in reach to FL90 and a square with sides of 40 NM around EBBR.The advantage of these data is that they are available in a database and that already some reporting tools exist for these data. 4.2.2
CDO TROUBLE REPORTS
4.2.2.1
CDO – TROUBLE REPORTS (BRUSSELS AIRLINES PILOTS)
Pilots from Brussels Airlines were asked to provide feedback on the trials via their central reporting database (SENTINEL).The concept of energy management is briefed and discussed with all pilots during pilot forums and via notifications in the cockpit briefing room. After each flight the pilot must enter his flight data in our main database for Flight Operations (Blue One). This is a rather complete flight update: •
Actual off-block time, actual take-off time, actual landing time, actual on-block time
•
Actual Zero Fuel Weight
•
Actual fuel uplift and actual fuel on landing
•
Flight Crew Report (FCR) for any specific issue affecting the flight (handling, catering, etc.). This is directly saved in a central database (SENTINEL) It has been asked to the pilots to use this electronic format to enter any CDO concern. All Brussels Airlines members participating to the B3 project have access to this database. It is then possible to make different queries to analyze one flight or a series of flights.
4.2.2.2
CDO – TROUBLE REPORTS (ATCOS)
ATCOs were asked to fill out eventual comments on a trouble report. At the ATCo’s working position a “Trouble report form“ is available, where ATCo’s can give comments on the CDO-trials.The template for the ATCo-trouble report is shown below.
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Figure 4-3 - CDO Trouble Report.
4.2.3
FLIGHT LISTS WITH INDICATION INDICATION OF CDOCDO-MARKED FLIGHTS
Within Belgocontrol the REDSTAR database contains a list with all flights arriving to Brussels Airport, with indication of the airline, the date and time, the aircraft type and the runway used. The REDSTAR database however does not contain information on wether an approach is CDO-approved or not.In order to be able to analyse the effect of CDOapproval, for the B3-project the information on CDO-approvals needed to be produced and added to the dataset. In order to generate the information on the flights marked CDO and to make this data available te following steps are followed: 1.
Identification of CDO-flights is done by marking those flights that got a CDOapproval. This marking is done by the ATCO on his/her CWP (Controller Working Position) of the Eurocat system.
2.
In order to make this information available the marked files are extracted from the Eurocat log-files. During this process also related data are extracted, such as the altitude of the aircraft at the moment of the “mark”-action.
3.
The extracted data for CDO-approved flights are transferred from the operational to the administrative network where they are added to a table CDATEST.The table CDATEST contains data from REDSTAR (reference flight database for EBBR) for all arrivals on the two runways used in the trials: 25R & 25L for the five airlines participating in the trials.For flights that received a CDO-approval, information from – Phase 2 Version 4.2 - 15/02/2012 - Page 28
B3 SESAR JU PROJECT the Eurocat system (see steps 1 & 2) is added. 4.
The resulting data are made available by Belgocontrol to the partners of the B3project and to the other four airlines participating in the trials.A dedicated software was developed to select the relevant data and to send these to each of the partners external to Belgocontrol. The data from the table CDATEST are also used within Belgocontrol to provide statistics and for analysis in EFICAT.
4.2.3.1
MARKING CDO-APPROVED FLIGHTS
As the tests are performed 24h/24h, but only when traffic permits, only some flights are CDO-approved.In order to allow for a post-analysis of differences between CDO and nonCDO-flights, the ATCOs give a Mark to the flights that received a CDO-approval.For this purpose the Mark-field available on the CWP (Computer Working Position) is used.Marking the flight is much easier for the ATCO compared to note the marked flights on a paper form.The pictures below show an example.
Move over label to open extended label Left click on call sign to open call sign menu Figure 4-4 - Marked-field on CWP.
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In the call sign menu • Left click on “MORE” • Left click on “MARK” Figure 4-5 - Marked-field on CWP (2).
4.2.3.2
EXTRACTING FLIGHT DATA FROM EUROCAT-LOGFILES FOR CDO-FLIGHTS.
The information on flights that are marked is not readily available for use.The information therefore needs to be extracted from the Eurocat-system. In the Eurocat-system, the marking-action is stored in a general purpose log file.Every day a new log file is started. In order to extract the data a CDO-dedicated program has been written by the Belgocontrol CANAC²-team.This program runs through the log files of day minus 10 (day -10) and provides a result file per day. The software program identifies flights that were “marked” CDO and extracts the associated flight plan data.From a separate multi-purpose log file, additionally the altitude at the moment of the mark is extracted, as well as the distance that the aircraft has travelled between the moment the mark-field is checked and the touchdown of the aircraft. For every day, a separate text file (CDO_YYYYMMDD.csv) is generated. The extracted data for CDO-approved flights are transferred from the operational to the administrative network, where they can be combined with the REDSTAR-flight data.
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B3 SESAR JU PROJECT 4.2.3.3
CORRELATE EUROCAT-DATA WITH REDSTAR-FLIGHT DATA
The extracted data for CDO-approved flights are transferred from the operational to the administrative network where they are added to a table CDATEST.The table CDATEST contains data from REDSTAR (reference flight database for EBBR) for all arrivals on the two runways used in the trials: 25R & 25L for the five airlines participating in the trials.For flights that received a CDO-approval, information extracted from the Eurocatlogfiles (see previous steps) is added. This part of the process is implemented and automated by the Belgocontrol REDSTARteam.An Oracle table CDATEST was made.A dedicated software is developed to systematically update the information in the table CDATEST. Daily, theCDATEST table is updated with data from 2 sources: REDSTAR and the abovementioned CDO_YYYYMMDD.csv-files. The REDSTAR database can be considered as the reference database with flight date.From REDSTAR, all the arrivals from participating airlines on the runways used in the trials: 25R a 25L are retrieved and stored in CDATEST.More specifically the following selection conditions are applied: • • • •
Movement = arrival Runway = 25L or 25R Airline = BCS, BEL, JAF, SQC or TCW (destination airport = EBBR)
For flights marked by the ATCO’s as CDO-approved, the table CDATEST is complemented with the extra data fields from the CDO_YYYYMMDD.csv-files. An example of the main data fields in such a result file is shown in the example below (Table 4-1). TIME_CDA DURATION 04:04:06 00:07:54 10:11:01 00:07:59 10:40:24 00:07:36 13:20:49 00:08:11 13:42:59 00:07:01 15:12:44 00:08:16 22:15:08 00:10:52 22:34:04 00:09:56 23:05:18 00:10:42 21:20:34 00:10:26 21:44:47 00:09:13 21:53:17 00:09:43 22:22:28 00:10:32
GDATE GHOURMIN 02/10/2012 412 02/10/2012 1019 02/10/2012 1048 02/10/2012 1329 02/10/2012 1350 02/10/2012 1521 02/10/2012 2226 02/10/2012 2244 02/10/2012 2316 03/10/2012 2131 03/10/2012 2154 03/10/2012 2203 03/10/2012 2233
CLS BEL245 BEL62F BEL2038 BEL82K BEL33P BEL26W BEL51G BEL32C BEL74F BEL15X BEL82H BEL74F BEL51G
VLTYPE A333 A320 RJ85 B734 RJ1H RJ1H RJ1H B733 B734 RJ1H A320 B733 RJ1H
IMMA OOSFM OOSNB OODJT OOVEP OODWI OODWH OODWB OOVEH OOVEP OODWA OOSNB OOVEN OODWD
RWY 25L 25L 25L 25L 25R 25L 25L 25R 25R 25R 25R 25L 25R
ALTITUDE TRACKMILES 88 32 81 32 131 31 84 28 87 29 98 32 91 31 84 34 112 43 144 37 66 30 109 41 105 36
Table 4-1 – Example - Main fields for Marked CDO-flights extracted from Eurocat log files. – Phase 2 Version 4.2 - 15/02/2012 - Page 31
B3 SESAR JU PROJECT 4.2.3.4
DISTRIBUTE FLIGHT LISTS WITH INDICATION OF CDO-MARKED FLIGHTS
Besides the use internally in Belgocontrol, the data from CDATEST are also used within the CDO-project by the different B3 and and by the other airlines participating in the CDO-trials. Brussels Airlines, as well as the other airlines involved in the trials receive information for their own flights.So separate files containing the CDO-approved flights for the individual airline are made to Brussels Airlines, DHL, Jetairfly, Thomas Cook and Singapore Airlines Cargo.Airlines could use these files for information and for further analysis. Brussels Airport and its’ subcontractor KU Leuven receive the CDO-approved flights for all the participating airlines.For each of the flights in these files, Brussels Airport prints HPFC and VPFC (see further under the description of the NMS-tool).Brussels Airport on its turn then provides these graphical printouts to corresponding airlines and to Belgocontrol as a visual reference for the vertical and horizontal trajectory followed by the flight. KU Leuven uses the CDATEST-information to distinguish between CDO-approved and nonCDO-approved flights when calculating the noise impact or when assessing the lateral position of arrivals. Dedicated software development For the distribution of the data to the partners external to Belgocontrol, Belgocontrol developed dedicated software.This software automates the extraction and e-mailing of the data from the table CDATEST. From the table CDATEST, each week an extract is sent to each of the participating airlines and to The Brussels Airport Company and its subcontractor KU Leuven.Each of the participating airlines receives information for their own flights.The Brussels Airport Company and its subcontractor KU Leuven receives data for all the flights.
4.2.4
ASTERIX CAT62 RADAR DATA
Besides the radar data available in the NMS (Noise Monitoring System), the second source for radar data that is used are rough radardata in the standard radar format Asterix Cat.62. The advantage of the Asterix Cat.62radardata is that they cover the whole of Belgium.A disadvantage is the huge file size of about 0.5 GB for one day of data. Asterix Cat.62 is also the default input format for analysis in the EFICAT CDO/CCO analysis tool. Prior to the B3-project asterix Cat.62 data were only available in the operational network and for a limited time, with no link to the EFICAT-tool. – Phase 2 Version 4.2 - 15/02/2012 - Page 32
B3 SESAR JU PROJECT For the B3-project, the Asterix Cat.62 radar data are made available by the Belgocontrol DGE (Directorate General Equipment). 1. Sample data analysis During phase 1, two samples of Asterix Cat.62 data were received from the Belgocontrol technical department for testing purposes.Both samples were for 9th of November 2010.One sample was for the period 0700-0800 UTC, the second sample was for the period 1700-1800 UTC.The size of these samples was respectively 22 and 20 Mbytes.The size of the basic data thus is quite significant. In order to import all the data and to keep these available for further analysis (not only for the B3-project); the most adequate way to import data was considered to be one day of data per database. During phase 2 this was further analysed.Radar data in the Asterix Cat.62 format are standard available per hour.For the B3-project data were combined into files for one day.The first day with these files available is 1st of April 2011.These one-day files, for dates between 1st April 2011 and 13 July 2011, have sizes varying between 380.000 kB and 570.00 kB 2. Making Asterix Cat.62 –data available for the B3-project The AsterixCat.62-data are originating from the operational network and cannot be accessed by the administrative network.For this reason the Belgocontrol ICT-department provided the necessary space a dedicated folder on the administrative network and developed an automated process to copy the Asterix-files from the operational to the administrative network. From this location the files are retrieved to be imported in the EFICAT CDO/CCO Analysis tool.
4.2.5 4.2.5.1
FDMFDM-DATA SETTING OF THE CONCEPT
Since 2005 the Flight Safety Department of Brussels Airlines runs a FDM program. Using recorded flight data this Flight Data Monitoring (FDM) program assists an operator to identify, quantify, assess and address operational risks and deviations from Standard Operating Procedures. Flight data is obtained from the aircraft’s digital systems by a flight data acquisition unit (FDAU) and routed to the crash protected flight data recorder (FDR). In addition to this mandatory flight data recording system, a second output is generated to a non-mandatory recorder. – Phase 2 Version 4.2 - 15/02/2012 - Page 33
B3 SESAR JU PROJECT This output is, depending on the aircraft type and installed avionics, often more comprehensive than that of the FDR due to the increased capacity and special features of this system. Unlike the FDR, this recording system has a removable recording medium. Because these are easy to gain access to, the non-mandatory recorders are known as quick access recorders (QARs). At Brussels Airlines, the QAR media are physically replaced every week, and sent to a central point at the Flight Safety Department for input and analysis. The disks are entered and replayed through dedicated computer programs starting with one that converts the raw binary data into engineering units. This is the physical backbone of the FDM program. This dedicated software is also used to design specific algorithms detecting deviations from accepted norms of flight operations and safety. Afterwards, such detected deviations help to find subtle trends and tendencies. A population of flights can be statistically analysed, specific flights can be studied thoroughly. As a result this FDM program is a closed loop system that provides a means for the permanent monitoring and improvement of the safety and performance of the flight operations. Recently this tool became part of the Safety Management System within Brussels Airlines. It has been demonstrated that the FDM program is a valuable proactive tool to improve the day-to-day monitoring of adherence to Standard Operating Procedures and the condition of individual aircraft. Lastly, this program take places in a de-identified way and is subject to signed agreements and working methods.The flight data utilized in this CDO project had the sole purpose of obtaining factual material to support the CDO analysis in an unbiased manner. It was not used for identification purposes of crews or to apportion blame.
4.2.5.2
TECHNICALITIES AND LIMITING FACTORS
Despite the large fleet, consisting of Avro RJ’s, Airbus A319, Airbus A320, Airbus A330 and Boeing B737, some limits during the B3 project have been noticed. First of all, not every aircraft recorded the essential parameters that could assist in our study of CDO’s. Secondly, the Boeing and Avro fleet are equipped with flight data acquisition units that can’t be customized. The required know-how and technical possibilities to update this to more exhaustive standards are considered very costly and outside the scope of any current project. Finally, differences in the applied decoding software tools and hardware required separate collection methods, algorithms and export features; complicating the process even more. After consideration and initial testing, only the A319/A320 and A330 fleet were retained for this project. The data integrity and availability of flight data parameters showed many – Phase 2 Version 4.2 - 15/02/2012 - Page 34
B3 SESAR JU PROJECT advantages. It also proved to be the type of aircraft operating day and night; helping us providing a wider spectrum of data. The expanding A319/A320 fleet within Brussels Airlines during this B3 project confirmed this choice even more. At the end twelve aircraft were collecting data for the B3 project. Five different Airbus A319/320 and five Airbus A330-301/A330-322 took part in this part of the project.
4.2.5.3
EXTRACTION OF FDM-DATA – IN HOUSE DEVELOPMENT OF AN ALGORITHM
In order to handle the large amount of data in a user-friendly way, the flight data analyst opted to design a particular data collection algorithm via his FDM program. This also prevented a negative impact on the main purpose of the FDM program: flight safety. Every recovered inbound flight triggered this algorithm when crossing a certain flight level. FL100 was agreed upon as the realistic boundary for the situation in Brussels within the B3 project. The segment stopped as soon the aircraft was passing the outer marker, as this moment clearly represents a common end of the approach. Throughout an approach, several parameters like aircraft registration, landing runway, times, aircraft weight, several sorts of speeds, engine power, air data, descent rates, headings and fuel figures were collected. Additionally, other variables for this segment were derived and averaged in the meantime.Those were parameters like: ambient temperatures, power settings, groundspeeds, gradients and even accurate track miles. Finally, the use of anti-ice systems, flap settings, landing gear and spoilers -when recorded-were registered and timed as well. This in order to find out if conclusions based on this flight data could be matched with CDO marked flights. The algorithm from the FDM program calculated several additional parameters, which after export, could be used to compare with the results obtained by the EFICAT-CDOanalysis by Belgocontrol. This EFICAT-CDO-analysis tool is based on radar data, whereas FDM data is based on on-board recorded flight data. The aim of this comparison was to compare the fuel/CO2 estimates by the EFICAT-CDO-analysis tool with the fuel calculated from the FDM program. For this project, Brussels Airlines extracted data from the FDM program in two different ways. Most detail was needed for the calculation of the noise impact (6) and the analysis of individual flights (3). Secondly, a unique algorithm was programmed which was used for a broader analysis. (4) Both types of treated flight data were made available by Brussels Airlines to both Belgocontrol and Brussels Airport. Brussels Airlines retrieved specific flight data of individual flights. Typically, 50 particular parameters were collected every second as soon as the descent into Brussels was initiated. – Phase 2 Version 4.2 - 15/02/2012 - Page 35
B3 SESAR JU PROJECT FDM-data for specific flights were made available by Brussels Airlines to both Belgocontrol and Brussels Airport’s subcontractor KU Leuven.These files were handpicked, since they require manual creation. The analysis of the FDM-data by Belgocontrol aimed for a better understanding and comparison of optimum profiles, related fuel consumption and CO2-production.KU Leuven used the data for acoustic simulations with the software INM.
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B3 SESAR JU PROJECT 4.3
TOOLS
4.3.1
NMS (NOISE MONITORING MONITORING SYSTEM), SAS AND GIS GIS
4.3.1.1
DESCRIPTION OF THE NMS
The Noise Monitoring System (NMS) operated by The Brussels Airport Company operates, collects, controls and interprets noise data from a network of noise monitoring terminals (NMT’s) on and in the surroundings of Brussels Airport. The NMS also functions as a track keeping system as it correlates noise-, radar-, weather- and flight information.The radar data (smoothed x-, y- and z- radar data) that feeds the NMS daily is provided by CANACBelgocontrol. The area for which data is provided is limited within a square of maximum 40 nautical miles and up to an altitude of maximum FL90. The reporting module within the NMS is a tool to visualize flight trajectories vertically (VPFC) and horizontally (HPFC) in standardized reports.
Figure 4-6 - VPFC. – Phase 2 Version 4.2 - 15/02/2012 - Page 37
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Figure 4-7 - HPFC.
4.3.1.2
NMS-REPORTS AS BELGOCONTROL
A
REFERENCE
FOR
AIRLINES
AND
For each of the CDO-marked flights, Brussels Airport printed (in pdf) a VPFC (Vertical Projected Flight Curve) and a HPFC (Horizontal Projected Flight Curve) with their NMS (Noise Monitoring System).Brussels Airport provided these reports to the corresponding airlines and to Belgocontrol
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Figure 4-8 - Visual detection of a non-CDO (VPFC).
Figure 4-9 - Figure 5.9 : Visual detection of a CDO (VPFC).
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B3 SESAR JU PROJECT As the vertical profile (<=FL90) is a perfect tool to spot intermediate level offs, it gives an indication of the precision of the CDO flown. Within the airlines the visual information was used to evaluate the descent profiles and for personal discussion and briefing on individual flights with the corresponding pilots. Within Belgocontrol, the HPFC and VPFC printouts were used to obtain a feeling with the diversity of flown profiles in case of CDO-approval and also as reference data during data analysis.
4.3.1.3
NMS-RADARDATA TO COMPARE LATERAL ROUTES FOR CDOAPPROVED AND NON-CDO-APPROVED FLIGHTS USING SAS AND GIS
NMS-radardatawere used to investigate if the ground track position of CDO approved approaches and non-CDO approved approaches differ or not.To analyse this, the HPFC’s of CDO and non-CDO flights are compared to each other.In this analysis it was important to take into account that no other parameters influence the HPFC’s of the compared flights.A SAS (Statistical Analysis Software) database is created containing the ground tracks of the different CDO and non-CDO flights, which allow to filter a group of flights.A graphical presentation of these tracks is made in a GIS (Geographical Information System) environment and visually analysed.
4.3.2 4.3.2.1
EFICAT CDO-EVALUATION BY EFICAT
The CDO/CCO Tool is an off-line tool, which is designed to provide analysis of Continuous Descent Operations, using radar data as inputs.Users can load their own radar data, and extract statistics about CDO/CCO from which reports can be produced.Though the CDO/CCO Tool is designed to analyze Continuous Descent Operations, by analogy the CDO/CCO Tool also has some means to analyze continuous climbs. The Eficat tool analyses radar data.Most direct parameter calculated is level flight.This allows e.g. identify segments of level flight as a proxy to estimate if a flight is performing a CDO or not. The print-screens below show an example of an EFICAT analysis. As can be seen in the top part, the EFICAT tool allows a certain but limited filtering of the data.
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Figure 4-10 - EFICAT Analysis part1.
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Figure 4-11 - EFICAT Analysis part2 (scrolled to the right).
4.3.2.2
FUEL BURN ANALYSIS POSSIBILITIES WITH EFICAT
The fuel burn calculation uses all radar plots within a configured parameter radius of the ADES.The default distance in EFICAT is 150 NM, but can be adapted e.g. to take into account smaller airspaces, or partial continuous descents.The rationale for starting at these static radii is to allow comparison between similar aircraft types at different airports, as well as flights using a particular arrival route at the same airport. In this way, actually the combined effect from the lateral route and the vertical profile is measured. The calculation of fuel is done using BADA-fuel burn data expressed in Kilograms per Minute (kg/min), based on the radar plot flight levels, time of flight and the phase of flight (cruise, descent, â&#x20AC;Ś).Nominal aircraft weights are used.
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B3 SESAR JU PROJECT 3 types of fuel amounts can be calculated in EFICAT: o
The total fuel burn from the configured parameter radius (e.g. 150 NM) until a Minimum plot cutoff altitude (e.g. 1500 ft)
o
The fuel burn between the configured parameter radius until (and including) a "above/below altitude cutoff" parameter (e.g. FL100)
o
The fuel burn below a "above/below altitude cutoff" parameter (e.g. FL100 and a Minimum plot cutoff altitude (e.g. 1500 ft)
The latter one (bold) is used in the B3-project.
4.3.2.3
RADAR-DATA VISUALIZATION IN EFICAT
Radar-data can be visualized as horizontal plot, as vertical profile or in perspective.Examples are given below.
Figure 4-12 - EFICAT â&#x20AC;&#x201C; Example of Horizontal Plot.
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Figure 4-13 - EFICAT - Example of Vertical Plot.
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Figure 4-14 - EFICAT - Example of Perspective Plot.
4.3.2.4
AGREEMENT WITH EUROCONTROL TO TEST THE EFICAT TOOL
Belgocontrol has closed an agreement with Eurocontrol to use the CDO/CCO Tool to assess Continuous Descent Operations (“CDO”) performance, on the condition of providing to Eurocontrol any suggestion for improvement.
4.3.2.5
IMPORT OF RADAR DATA IN EFICAT FOR THE B3-PROJECT:
a)
Data in the standard radardata format Asterix Cat.62 were used.Asterix Cat.62 also is one of the standard input formats for the EFICAT CDO/CCO analysis tool.
b)
On the 22nd of December 2010, the EFICAT-tool was installed and the import of Asterix 62-data was trained and tested successfully. Importing the Asterix Cat.62 radar data in EFICAT is a time consuming process. On average it takes about 3 hours to import one day of data.So in the optimum case 3 days can be loaded in one working day.About 90 days of data were imported in EFICAT.All available Asterix data for the months of April, May and June 2011 were loaded, as well as selected days for July 2011.After importing in EFICAT, for each – Phase 2 Version 4.2 - 15/02/2012 - Page 45
B3 SESAR JU PROJECT imported day a separate database is available. c)
The Asterix Cat.62 data do not contain any information to identify if the arrival was CDO-approved or not.Therefore it was expected that it would not be possible to use the information from marked flights for the global analysis. However a solution for this was found.Output from the EFICAT-tool was combined with 2 other data sources: data from the table CDATEST and data from the reference database REDSTAR.The combination of EFICAT data with these two additional sources was done in MS-Excel.
d)
From this combined dataset.A sample of flights was selected for individual analysis.The sample contains some CDO-flights (both marked a not marked) and some non-CDO-flights (both marked and not marked).The conclusion if a flight is considered CDO or not is the result of the analysis with EFICAT.
4.3.2.6
EFICAT ANALYSIS PERFORMED FOR B3-PROJECT
The analysis performed in the B3-project focused on the flight portion below FL100, with intermediate steps at FL80 & FL60.The used low-cut altitude was 1500 ft.This choice was made because the lowest ILS interception altitude at EBBR is 2000 ft and with a CDO no changes are applied for the flight portion where the aircraft is on the ILS. Within EFICAT Asterix cat.61 data, starting from 1st of April 2011 are imported. Importing one day of Asterix cat.61 data takes a considerable time.After some measures the time for the import of one day of data could be reduced to +/- 3 hours (depending on the size of the file). Measures taken are: PC with larger C:-drive, copying the raw Asterix files from the network drive to one of the PC’s hard disks and starting the PC with a minimum of programs running in background, The import of the AsterixCat.62 data in EFICAT results in one database per day. For each database/day, 3 analyses are run in EFICAT: -
below FL60 below FL80 below FL100
In each of these analyses EFICAT calculates as set of results.For example in the analysis “below FL100” the results are: -
DIST-A: distance flown below FL100 (and above 1500 ft) DIST-B: distance flown level below FL100 (and above1500ft).When level flight < 2.5 NM, then value is 0. Time-A: Time flown below FL100 (and above 1500 ft) Time-B:Time flown level below FL100 (and above 1500 ft).When level flight < 2.5 NM, then value is 0. Fuel kg: Fuel burn calculated by EFICAT for time flown between FL100 & 1500ft – Phase 2 Version 4.2 - 15/02/2012 - Page 46
B3 SESAR JU PROJECT -
Angle: average descent angle calculated by EFICAT for time flown between FL100 & 1500ft dB40: difference in noise based on altitude difference.Reference = FL40 with 3°, compared to real altitude at this position dB80: difference in noise based on altitude difference.Reference = FL80 with 3°, compared to real altitude at this position CO2-emission calculated by EFIAT for time flown between FL100 & 1500ft
For the FL60 & FL80 the same parameters are calculated but then for the flight portion between respectively FL60-1500 ft and FL80-1500 ft.
4.3.2.7
EXPORT OF THE EFICAT RESULTS TO MS EXCEL FOR FURTHER ANALYSIS
During B3-phase I the intention was to analyse the results in EFICAT within the EFICAT-tool only. However in B3-phase II a better solution was found and implemented.This solution was to: • export the EFICAT-results to MS Excel • offline combine the EFICAT results with additional data sources • make a global analysis in Excel 1. Export to MS Excel: For each day of data (+/- 90 days), three EFICAT-analyses were run: one for FL60, one for FL80 and one for FL100.For each of these runs an export was made, resulting in about 90 x 3= 270 MS Excel files which were subsequently combined into 3 files (one per month). 2. Offline combination with additional relevant data: The data from CDATEST, containing information on flights marked by the ATCOs was combined with the exported EFICAT-results.From REDSTAR the following reference data were also added to the EFICAT-results:gdate, cls, rwy, ccls, imma, vltype, mtow, cie, ldate, lday, lday_int, lweek, lhourmin, lhour.The most important being CCLS and RWY.CCLS is the flight code as it is used within Brussels Airlines.The value for CCLS typically slightly differs from the value for CLS, the callsign code used by Belgocontrol.Addition of CCLS to the dataset helped Brussels Airlines to link the EFICAT information to their own data.The runway field was important e.g. as it allows to compare between runways included in the CDO trials and runways not included in the CDO-trials. 3. Make global analysis in MS Excel: In MS Excel the combined dataset is used to analyse the data
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B3 SESAR JU PROJECT 4.3.3
SQL &MS &MS EXCEL FOR THE STATISTICAL ANALYSIS OF OF CDOCDOAPPROVALS AND OF EFICAT EFICATCAT-RESULTS
For use within Belgocontrol, the data in the CDATEST-table in REDSTAR can be accessed using SQL and results were exported to MS Excel for further analysis. MS Excel was also used by Belgocontrol to correlate exported results from the EFICAT tool with data in the CDATEST-table and for subsequent statistical analysis of the resulting dataset e.g. on the percentage of CDO-approvals, on the FL (Flight Level) from which CDOs are approved and the average time between the marking of the CDO-flight and touchdown.
4.3.4
MS EXCEL FOR DESCENT PROFILE ANALYSIS OF FDMFDM-DATA
4.3.4.1
USE OF FDM-PARAMETERS.
For a number of selected flights, the vertical profile of the actually flown descent has been analyzed, using real FDM data, provided by Brussels Airlines. The objectives of this exercise: 1. Detailed determination of the fuel consumption during descent, starting at the Top-OfDescent (TOD), regardless whether or not a continuous descent has been flown. 2. Evaluation of the impact of a (partial) CDO on the overall descent fuel consumption. 3. Detection of flight practices which lead to fuel consumption inefficiencies. In this section of the report, the methodology (with its constraints) is outlined. For each analysis, following parameters, as recorded on board of the aircraft, were used: Parameter Name
Description
Use of the data
TIME_R
Time Reference of recorded data
This reference is used for calculations and integrations.
FLIGHT_PHASE
Flight Phase
Flight phase determination. The TOD is considered to correspond with the transition from CRUISE to DESCENT, unless this transition happens more than 200 NM from the destination airport (ADES).
TAS
True Air Speed (kt)
TAS is used to calculate the “air distance”. Difference with the “track distance” allows quantify the effect of wind.
IASC
Indicated Air Speed (kt)
IAS is used to evaluate differences with the reference profiles which are based on specific IAS value(s).
GSC
Ground Speed (kt)
GS
is
used
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to
calculate
all
the
time
“track
B3 SESAR JU PROJECT distance”. MACH
Mach Number
N11C – N12C
N1 - engine 1 and 2
ALT_STDC
Altitude (non-baro corrected)
GWC
Gross Weight
GW at TOD determines the reference descent profiles.
LDGL/R
Landing Gear status (Air/ground)
The transition from Air to Ground is used to determine the landing point, and to calculate the baro correction.
SPD_BRK
Speed brake activation
Activation of the speed brake is recorded, but the recording does not show to which extent it has been deployed.
FF1C – FF2C
Fuel Flow Engine 1 and 2 (kg/h)
Fuel burn is calculated by integration of the instant fuel flow (FF) values of both engines.
FQTY
Fuel Quantity (kg)
FQTY is used to crosscheck the fuel burn calculation based on fuel flow. The value is known to be less accurate than the FF readings, but allows to detect calculation anomalies.
Throttle activity visualisation, and indication that anti-ice could have been activated.
Table 4-2 - Use of recorded data items.
4.3.4.2
REFERENCE PROFILE CONSTRUCTION.
For each analyzed flight, the flown profile is compared to a known reference profile. Although the detailed operational parameters (i.e. cost index, and chosen descent speed(s)) are not known, this comparison allows to detect inefficiencies linked to the fact that the flown profile deviates from a CDO-one. The used reference profile is constructed as follows: 1. The baseline profiles are extracted from the AFM of the subject aircraft. See Appendix 4 for the profiles related to the Airbus A319; see Appendix 5 for those related to the Airbus A330-300. These profiles represent, for two typical masses, a nominal descent pattern: a. A319: descent at M.78 above the crossover altitude; at 300 KIAS3 below the crossover altitude; at 250 KIAS below FL100.
3
: KIAS = Knots (kt) Indicated Air Speed – Phase 2 Version 4.2 - 15/02/2012 - Page 49
B3 SESAR JU PROJECT b. A333: descent at M.80 above the crossover altitude; at 300 KIAS below the crossover altitude; at 250 KIAS below FL100. 2. For each flight the reference profile is linearly interpolated (or extrapolated), taking into consideration the value of the GW of the aircraft at the TOD. The output comprises values for horizontal distance, flight time and fuel consumption. The resulting reference frames will normally fit within the colored contours shown in Figure 4-15unless the mass of the aircraft at TOD falls outside the given range (exceptions). The reference profile does not cater for wind, and does not include corrections to take into account particular airframe characteristics of the specific aircraft used for the investigated flight.
Figure 4-15 - Reference Descent Profiles.
4.3.4.3
ANALYSIS DESCRIPTION.
For each analysed flight, four graphs are provided: Descent profile: This graph shows the flown vertical profile versus the calculated reference profile. In addition, the selected thrust (Throttle - N1) and speed brake activation are shown. The landing point is shown at the ‘origin’ (0,0) of the graph. The value for the selected thrust gives an indication about possible selection of engine antiice during the descent. Note that “total engine anti-ice” may account for an increase of up to 70% in the nominal fuel consumption for descent! – Phase 2 Version 4.2 - 15/02/2012 - Page 50
B3 SESAR JU PROJECT A typical example is given inFigure 4-16.
Figure 4-16 - TypicalDescent Profile graph. In this particular example, the aircraft initiated a reduced descent, well in advance of the reference profile TOD, till reaching this profile just below 25.000 ft altitude. Below 25.000ft, we see the aircraft descending slightly below the reference profile. The speed brake was activated at glideslope interception, in the final stage of the approach. The right axis is used for the thrust setting, while the left shows the altitude. Descent profile (time): This second graph shows again the descent profile, not referenced against track distance, but against time before landing. Figure 4-17shows the same descent as depicted Figure 4-16. Note that the flight started its descent some 4 minutes before the reference TOD.
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Figure 4-17 - Typical Descent Profile – Time graph. According to the previously explained rationale, one may expect a time/fuel penalty against the reference profile. This is shown in the third graph: Fuel burn analysis: The third graph (see Figure 4-18for an example) shows the descent path again, but now only until 1.500 ft AGL. In addition to the ‘descent profile’ referenced to terrain (ground), also the ‘air-distance’ is shown (Missing for some airframes, due to an observed FDM-anomaly). In this particular example, we see a significant difference between both profiles above 25.000 ft (tailwind), but no difference below that altitude. This practically means that the reference profile is perfectly valid below 25.000 ft, but should be used with caution above this altitude. Two fuel burn curves are provided: 1. The red curve displays the real fuel burn up to a given point in cruise. 2. The brown curve shows the theoretical fuel burn, provided the reference profile should have been flown up to the same point.
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B3 SESAR JU PROJECT
Figure 4-18 - TypicalDescent Profile â&#x20AC;&#x201C; distance graph. The common reference point is taken at the end-of-descent (EOD) point, defined at 1500 ft above the threshold of the landing runway at the destination airport. The difference between both curves represents the fuel burn penalty (or gain) at the same distance from the EOD. Fuel burn during the cruise portion of the reference fuel burn curve is calculated using the average fuel burn figure at the end of the cruise phase of flight, taking into account the average ground speed of the corresponding cruise leg. The fuel penalty for the descent shown in Figure 4-18has been calculated to be 67.4 kg, mainly due to the early descent of the aircraft. This is merely an indication rather than a fully exact figure, as no wind has been taken into account for the reference descent path calculation. Especially if the wind is significant, this value should be read with caution! Indicated air speed throughout the descent is provided as additional information. In order to assess the continuous descent effects below 15.000 ft, a detailed graph of the final descent profile is given as well: see Figure 4-19. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 53
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Figure 4-19 - Typical Fuel Burn below FL150 graph. In this particular case we observe a slight fuel burn increase, probably due to the fact that the aircraft remained below the reference profile. Note that the crew initiated the speed reduction down to 250 KIAS well below FL100. The graphs clearly reveal which flight related events during the descent result in extra fuel burn. Important Notice: Operational constraints and instructions from ATC, possibly preventing the flight crew from performing the descent as intended, could NOT be taken into account in this analysis process. As a result, the authors cannot and do not want to attribute any observed ‘event’ to any involved party in this process.
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B3 SESAR JU PROJECT For each of the analyzed flights, some key values were derived from the FDM data: Actual fuel burn in descent against the corresponding values of the theoretical reference descent profile between: a) FL100 and 1500 ft AGL b) FL80 and 1500 ft AGL c) FL60 and 1500 ft AGL Flown track distance in descent between: a) FL100 and 1500 ft AGL b) FL80 and 1500 ft AGL c) FL60 and 1500 ft AGL
4.3.5
INM (INTEGRATED NOISE NOISE MODEL) FOR NOISE CALCULATION CALCULATION
KU Leuven, subcontracted by Brussels Airport calculated the noise impact with the INM (Integrated Noise Model).KU Leuven used exported FDM data from Brussels Airlines as an input and Belgocontrol data to distinguish between CDO and non-CDO-approved flights on one hand and on the other hand between flights that are or are not judged CDO by the EFICAT tool.
4.3.5.1
CALCULATION MODEL
For the evaluation of the potential noise benefit of CDO compared to non-CDO approaches the Integrated Noise Model (INM) of the Federal Aviation Administration (FAA) is used.This software tool is worldwide used to calculate the noise in the vicinity of airports due to departing and arriving aircrafts.Also in the Flemish environmental legislation, this model is prescribed to calculate noise contours around the Flemish airports on a yearly basis.Since the middle of the nineties these calculations are executed by the LaboratoriumvoorAkoestiek en ThermischeFysica of the KU Leuven, for the major Flemish airports.In this way a lot of experience exists for the use of this model on Brussels Airport as the airport is located on Flemish territory. In this project INM 7.0b is used which is the most recent version of the software model and which is compliant with the European Civil Aviation Conference (ECAC) Doc 29 (3rd Edition) “Report on Standard Method of Computing Noise Contours around Civil Airports”.This new version includes among other things the new SAE-AIR-5662 “Method for Predicting Lateral Attenuation of Airplane Noise” and bank angle implementation.
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B3 SESAR JU PROJECT 4.3.5.2
GENERAL CALCULATION METHOD OF THE INM
A database of 139 main aircraft types is connected to the calculation model extended with a database of more than 200 sub aircraft types.The noise performance data of these aircrafts are stored in the database as noise-thrust-distance curves.These curves contain the noise emission (SEL or LAmax) at the position of the receiver in function of the distance between the aircraft and the receiver and the engine thrust of the aircraft (see figure below).During the calculation process these curves are corrected for the meteorological conditions influencing the noise propagation in the air and, for the SEL parameter, also for the actual speed of the aircraft.
Figure 4-20 - INM 7.0b noise-thrust-distance curves for approach of the Airbus 330-301 with GE CF6-80 E1A2 engines. At each receiver position the aircraft-receiver distance, the engine thrust and the speed of the aircraft are determined at the moment of the shortest receiver â&#x20AC;&#x201C; ground-track distance during the flight of the aircraft (see figure below).
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Figure 4-21 - Determination of the shortest receiver â&#x20AC;&#x201C; ground-track track distance during approach. In summary, these data is necessary as input in the INM model to predict the noise impact of an aircraft movement: Aircraft type Ground track of aircraft movement 3 different profiles o
Speed profile (speed as a function function of the track distance to the airport)
o
Vertical profile (altitude as a function of the track distance to the airport)
o
Engine thrust profile (engine power as a function of the track distance to the airport)
To create these 3 profiles for an individual flight (speed, altitude and engine thrust as a function of the track distance to the airport) different methods exist in INM. Firstly, for each aircraft type in the INM database a standard approach profile is available within the software model.The figure below shows this profile for the A330.As can be seen on the altitude profile this INM standard approach procedure contains a level step at FL30.The peak in the thrust profile after touchdown is caused by the use of reverse thrust to decelerate the aircraft on the runway.
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Figure 4-22 - INM 7.0b standard approach profile for the Airbus A330-301 (thrust, speed, altitude). For some aircraft in the INM database these 3 profiles can be created by entering the different steps of the total approach procedure (Level, Level-Decel, Level-Idle, Descend, Descend-Decel, descend-Idle, Land, Decelerate, ...) in the model, the so called procedural profiles.For each step of this procedure some parameters must be known (speed, flap settings ...).Based on this data and the SAE-AIR-1845 equations, the corresponding thrust is calculated within the model.In this case the flap coefficients for the aircraft type must be available.For the airbus aircrafts in the database of INM, these coefficients are available since the 7.0b version. A third and last method to build the speed, altitude and thrust profiles is to enter these parameters directly into the model if these data (speed, altitude and thrust) are known for the approach under study.These profiles are called the fixed point profiles. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 58
B3 SESAR JU PROJECT 4.3.5.3
METHOD USED TO COMPARE THE NOISE IMPACT OF CDO AND NON-CDO APPROACHES
For the evaluation of the noise impact of aircraft approaching Brussels Airport the flights for which FDM data was retrieved from the aircraft were simulated in INM using fixed point profiles.The Belgocontrol data isused to distinguish between CDO and non CDO-approved flights.The text below shows how the necessary INM input data is retrieved for the individual flights. 1. Ground track The Brussels Airlines FOQA data contains the position (latitude / longitude) of the aircraft for each time stamp.However, examples of A330 approaches have shown that an offset might exist between the indicated and the true position of the aircraft (see figure below).This offset can be corrected by the knowledge of the time stamp of touchdown (FDM data) and the runway (NMS) or by the radar data available in the NMS. Radar (NMS)
FOQA FDM--shifted shifted FOQA FDM
Figure 4-23 - Ground track of an A330 approach on runway 25L at Brussels Airport. 2. Speed Profile INM requires the true airspeed as a function of the track distance to the runway.The FDM data of Brussels Airlines includes this speed for each time stamp.Combination of this data with the ground track (position and time stamp) allows us create the speed profile.An example for an A330301 approach is shown in the figure below. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 59
B3 SESAR JU PROJECT
400 350
250 200 150 100 50
True Airspeed [kts]
300
0 -350
-300
-250
-200
-150
-100
-50
0
distance [1000 ft]
Figure 4-24 - Example of a speed profile for an A330 non-CDO approach on Brussels Airport. 3. Altitude profile INM requires the altitude above ground level as a function of the track distance to the runway.The FOQA data contains for each time stamp two fields with an indication of the altitude of the aircraft: the radar altimeter and the altitude derived from the atmospheric pressure.Data from the radio altimeter are very exact, but can only be used below 2500 ft.For the higher levels, the altitudes from the atmospheric pressure (corrected for the altitude of the airport above sea level) will be used.The combination of this data with the ground track (position and time stamp) allows us to build up the altitude profile. An example for an A330-301 approach is shown in the figure below.
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B3 SESAR JU PROJECT 16000 14000
10000 8000 6000
Altitude [ft]
12000
4000 2000 0 -350
-300
-250
-200
-150
-100
-50
0
distance [1000 ft]
Figure 4-25 - Example of an altitude profile for an A330 non-CDO approach on Brussels Airport. 4. Thrust profile INM requires the corrected net thrust (CNT) per engine as a function of the track distance to the runway.Among all necessary data, this profile is the most difficult to create.However the FOQA data contains information about the engines rotation speed and about the engines fuel consumption, no simple and reliable relationship exists between these parameters and the CNT of the engine. The correct way to calculate the CNT values during approach is to solve the equation of motion of the aircraft where CNT is determined to “balance” the other forces weight, deceleration and drag and lift. In a simplified way (see ECAC Doc.29 3rd Edition - Volume 2 - Appendix B Eq B-20), this equation can be written as
where the drag and lift forces are expressed in the form of drag-over-lift coefficients (R). In INM 7.0b, these coefficients are available for the airbus aircrafts for different flap settings (Flap Coefficients).
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B3 SESAR JU PROJECT Necessary FDM data fields to solve this equation are: Time stamp Position (latitude, longitude) Altitude Speed (TAS, GSC) Weight of the aircraft Flap setting Atmospheric pressure and temperature For the individual CDO and non-CDO flights LAmax noise contours are calculated following the procedure described above.The LAmax parameter represents the maximum value of the A-weighted sound pressure level if an aircraft flies over.Noise contours connect these points on the ground that have the same LAmax value. The noise impact of the CDO and non CDO flights of the same aircraft type approaching the airport are compared in two different ways. 1) Surface of the noise contours 2) LAmax level difference at different track distances to the runway and at the different lateral positions to the ground track.
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B3 SESAR JU PROJECT 4.4
SELECTION OF DATA SAMPLE SAMPLE FOR DETAILED ANALYSIS ANALYSIS
. For detailed analysis of FDM data, both in MS Excel and in INM, a random sample was identified aiming to contain equal numbers of flight for the following combinations, separately for A139 and A333: • 10 CDO-marked and concluded CDO in EFICAT • 10 CDO-marked and not concluded CDO in EFICAT • 10 not-CDO-marked and concluded CDO in EFICAT • 10 not-CDO-marked an not concluded CDO in EFICAT This is summarized in the tables below. A319 Conclusion EFICAT-tool CDO-approved by ATC
CDO
No-CDO
Totals
Y (marked)
10
10
20
N (not-marked)
10
10
20
Totals
20
20
40
A333 Conclusion EFICAT-tool CDO-approved by ATC
CDO
No-CDO
Totals
Y (marked)
10
10
20
N (not-marked)
10
10
20
Totals
20
20
40
Due to the quickly expanding A319/A320 fleet and a few decoding issues with the software, some aircraft were not used for this project (OO-SSQ and OO-SSR). Furthermore, other individual flight data that could not be retrieved due to technical issues (OO-SSP).Therefore these aircraft were removed from the sampling process. The sample was then extended to a total of 46 flights.For 33 from these 46 flights flight data could be retrieved.The resulting sample for A319-arrivals is given in the table below.
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B3 SESAR JU PROJECT A319 Conclusion EFICAT-tool CDO-approved by ATC
CDO
No-CDO
Totals
Y (marked)
10
6
16
N (not-marked)
8
9
17
Totals
18
15
33
For the A333, recorded flight data for 23 out of the 40 selected A333, could be retrieved.The table below gives the distribution for these 23 arrivals with A333. A333 Conclusion EFICAT-tool CDO-approved by ATC
CDO
No-CDO
Totals
Y (marked)
7
5
12
N (not-marked)
4
7
11
Totals
11
12
23
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B3 SESAR JU PROJECT 5.
DATA ANALYSIS RESULT S
5.1
SCOPE OF THE TRIALS - 1 JULY 2009 – 31 OCT 2011
5.1.1
DESCRIPTION
Five airlines participated in the CDO-trials: CDO trials: Brussels Airlines, Jetairfly, Thomas Cook, DHL and Singapore Airlines Cargo. The trials were performed on the runways 25L & 25R. In the period, starting 1st of July 2009 until 31st of October ctober 2011 89.557 arrivals were performed by participating airlines on either the runway 25R or 25L. This is 33 % of all arriving traffic.
Figure 5-1 - All arrivals at EBBR (1 Jul. 2009 – 31 Oct.2011).
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B3 SESAR JU PROJECT
Figure 5-2 - All arrivals at EBBR (%) (1 Jul. 2009 31 Oct.2011). From this 89.557 arrivals by participating airlines on the runways 25R and 25L, the largest amount, 70.283 flights, are arrivals from Brussels Airlines. Jetairfly, Thomas Coos, DHL an Singapore Airlines Cargo respectively performed 8.668, 6.002, 3.888 and 716 arrivals on runways 25R and 25L in the period from 1st of July 2009 until 31st of October 2011.
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Figure 5-3 - Participating airlines, arrivals on RWYs 25R/ (1 Jul. 20092009 31 Oct.2011).
5.1.2
SUMMARY AND CONCLUSION CONCLUSION FOR POINT 5.1 5.1
Participating airlines, arriving on 25R and 25Lrepresent 33% of the traffic at EBBR.This means that the trials are open to one third of the arrivals.From the start of the trials until 31st of October 2011 this is a total of 89.557 89 arrivals.
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B3 SESAR JU PROJECT 5.2
CDOCDO-MARKED FLIGHTS - 1 JULY 2009 – 31 OCT 2011
The current section deals only with the data-subset for arrivals by participating airlines on the runways 25R & 25L. CDO facilitation by ATC is only possible when the traffic situation allows for it. Typically this will be in less busy traffic periods, and also depends on the type of traffic. Therefore only part of the arrivals by participating airlines on the runways 25R/25L will get an ATC approval to perform CDO. Arrivals facilitated by ATC to perform a CDO are marked by the ATCO. The left hand part of Figure 5-4 shows that between 1st of July 2009 and 31st of October 2011, ATCOs facilitated a total of 5.407 CDOs. The right hand part Figure 5-4 zooms into the current year 2011. In the first 10 months of 2011 already 3094 CDOs were facilitated by ATC. This equals 9% of the total number of arrivals by participating airlines on the runways 25R/L.
All (BEL, JAF, TCW, BCS, SQC) Share of CDO-marked 1 Jul. 2009 - 31 Oct.2011
All (BEL, JAF, TCW, BCS, SQC) Share of CDO-marked Jan. -> Oct 2011
marked 5407 6%
not marked 83988 94%
marked 3094 9%
not marked 31426 91%
Figure 5-4 - Share of CDO-marked flights for the 5 participating airlines (arrivals RWY 25R/L). 5.2.1
CDO MARKED FLIGHTS PER PER AIRLINE
The figures below provide for each of the five participating airlines the number and percentage of arrivals on runways 25R/L, both for the full period 1 July 2009 – 31 October 2011 and for the current year 2011 (until 31 Oct 2011). In 2011, for each of the participating airlines the percentage of marked CDOs has improved or at least remained equal compared to the total period from 1 July 2009 until 31 October 2011, showing a positive evolution in the number of marked CDOs. For DHL (BCS) the – Phase 2 Version 4.2 - 15/02/2012 - Page 68
B3 SESAR JU PROJECT percentage of CDOs marked is significantly larger than for the other airlines. This is because DHL has the highest proportion of night flights and during night the traffic situation more frequently permits to facilitate CDO. BEL Share of CDO-marked Jan. -> Oct 2011
BEL Share of CDO-marked 1 Jul. 2009 - 31 Oct.2011
not marked 66372 95%
marked 2274 8%
marked 3796 5% not marked 25132 92%
Figure 5-5 - Share of CDO-marked flights for Brussels Airlines (arrivals RWY 25R/L).
JAF Share of CDO-marked Jan. -> Oct 2011
JAF Share of CDO-marked 1 Jul. 2009 - 31 Oct.2011
not marked 8036 93%
marked 272 9%
marked 612 7% not marked 2926 91%
Figure 5-6 - Share of CDO-marked flights for Jetairfly (arrivals RWY 25R/L). TCW Share of CDO-marked Jan. -> Oct 2011
TCW Share of CDO-marked 1 Jul. 2009 - 31 Oct.2011
not marked 5545 93%
marked 217 10%
marked 440 7% not marked 1894 90%
Figure 5-7 - Share of CDO-marked flights for Thomas Cook (arrivals RWY 25R/L).
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B3 SESAR JU PROJECT BCS Share of CDO-marked Jan. -> Oct 2011
BCS Share of CDO-marked 1 Jul. 2009 - 31 Oct.2011
not marked 3357 87%
marked 318 21%
marked 522 13% not marked 1233 79%
Figure 5-8 - Share of CDO-marked flights for DHL (arrivals RWY 25R/L).
SQC Share of CDO-marked Jan. -> Oct 2011
SQC Share of CDO-marked 1 Jul. 2009 - 31 Oct.2011
not marked 678 95%
marked 13 5%
marked 37 5% not marked 241 95%
Figure 5-9 - Share of CDO-marked flights for Singapore Airlines Cargo (arrivals 25R/L).
5.2.2
EVOLUTION DURING THE TRIAL PERIOD
Figure 5-10and Figure 5-11 show a relatively high number of CDO-approvals in the months of July and August 2009. From September 2009 onward the number of CDO-approvals falls back, to recover again and to remain relatively stable from December 2010 onward. The drop in number of CDOs can be explained by the transition to a complete new air trafiic control system (CANAC²), asking full attention. Thanks to integration of the trials in the AIRE initiative with the B3-project, the CDO-trials received a new elan. In 2011 (until Oct.2011), there were between 149 and 381 CDO-approvals per month. Percentages are between 6% a month and 11 % a month.
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185 130 90 106 250 295 254 149 315 344 279 343 381 368 366
68 12 54 95 98 90 58 114 101
126 153
250
450 400 350 300 250 200 150 100 50 0
333
CDO-marked - evolution
07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 2009
2010
2011
Figure 5-10 - Evolution of the number of CDO-marked arrivals.
4% 2%
2% 1% 2% 4% 3% 4% 2% 3% 2% 5% 4% 3% 4%
6%
4% 5%
8%
7%
10%
6%
12%
10% 10% 9%
11%
14%
11% 9% 8% 9% 10% 9% 10%
% CDO-marked - evolution
0% 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 2009
2010
2011
Figure 5-11 - Evolution of the percentage of CDO-marked arrivals.
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B3 SESAR JU PROJECT 5.2.3
VARIABILITY FROM DAY TO DAY
For the most recent month of data the variability from day to day is illustrated in Figure 5-12, Figure 5-13 and Figure 5-14. The number of CDO-marked flights varies strongly from day to day. From Figure 5-13 it can be seen that the CDO-peakday in October 2011, counts 39 CDO-marked arrivals, while for 24th of October there were zero CDO-marked arrivals. An important reason is that the CDO trials are only performed on the runways 25R/L. From Figure 5-12 it can be seen that for some days there are no or very little arrivals by participating airlines on the runways 25R/L. Consequently the number of CDO-approvals will be very small or even zero. For example on 24th of October 2011 only 2 flights from participating airlines arrived on runways 25R/L. There were zero CDOs marked for this day. Figure 5-14 gives the percentage of CDO-marked flights. For normal days, the values vary between 0% and 25%. A special case is 13th of October 2011, where only 10 arrivals were performed on the runways 25R/L. 8 from these 10 arrivals received CDO-approval. Deeper investigation revealed that on 13th of October 2011, at 1h35 local time, the arrival runway changed from 25R/L to RWY 02. The 8 CDO-marked arrivals were all performed during the night period.
133 145 162 158 122 116 108
137 149 147 149 156 113 103 74
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200 180 160 140 120 100 80 60 40 20 0
120 113 146 158 147 155 162 113 114 150 153 146
Total - Variability per day (LT) October 2011
Figure 5-12 - Total amount of arrivals (participating airlines on RWY 25R/L; Oct.2011).
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CDO marked - Variability per day (LT) October 2011 40
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Figure 5-13 - Number of CDO-marked arrivals per day (Oct.2011).
5% 4% 8% 10% 2% 7% 13% 15% 20% 0% 6% 9% 6% 25% 15% 8% 6%
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100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%
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% CDO marked - Variability per day (LT) October 2011
Figure 5-14 - Percentage of CDO marked arrivals per day (Oct.2011). 5.2.4
VARIABILITY AMONGST THE HOURS OF THE DAY
Analogous to the figures on variability per day, the figures Figure 5-15, Figure 5-16 and Figure 5-17 respectively give: the total average amount of arrivals per hour by, the average number of CDO marked flights per hour and the % of CDO marked flights. Data are for the first 10 months of the current year 2011. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 73
B3 SESAR JU PROJECT It should be stressed that the figures are a subset from the total set of arrivals at EBBR, containing only the arrivals by participating airlines on the runways 25R/L. The arrival peaks at 08-09h and 18-19h in Figure 5-15 are due to arrival peaks at these moments for Brussels Airlines. Even though Figure 5-15 only contains 33% of the total arrival data for EBBR, the influence of busy landing hours on the amount of CDO marks can be seen in Figure 5-16, with low average numbers of CDOs approved in the hours 08-09h and 18-19h. This effect is even more clearly expressed in Figure 5-17. The hours 08-09h and 1819h show that on the average only 1%, and 2% arrivals are marked CDO. For other hours the average percentage of marked CDOs is from 6% up to 24%.
Total - Per hour of the day (LT) Jan. -> Oct.2011 16 14 12 10 8 6 4 2 0
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Figure 5-15 - Average amount of arrivals per hour (participating airlines on RWY 25R/L; Jan. -> Oct.2011).
CDO marked - Per hour of the day (LT) Jan. -> Oct.2011 1.4 1.2 1 0.8 0.6 0.4 0.2 0
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Figure 5-16 - Average amount of CDO-marked arrivals per hour (Jan. -> Oct.2011).
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% CDO Marked - Per hour of the day (LT) Jan. -> Oct.2011 30% 24% 23%
25% 20%
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15%
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10%
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9% 8%
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Figure 5-17 - Average % of CDO-marked arrivals per hour (Jan. -> Oct.2011). 5.2.5
VARIABILITY AMONGST THE WEEKDAYS
Bearing in mind that the considered dataset contains only 33% of all arrivals, namely those executed by participating airlines on the runways 25R/L, the distribution of the flights over the weekdays can clearly vary from month to month. This can be seen in Figure 5-18. Averaging over the total period of 10 months in 2011 however shows that Saturday and Sunday have the lowest number of arrivals on runways 25R/L for the participating airlines. This reflects the fact that there is less traffic in the weekend compared to weekdays. The average number of CDOs marked per weekday, as represented in Figure 5-19, is more constant. This means that the average percentage of CDOs approved is the highest in the weekend. This is shown in Figure 5-20.
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Number of arrivals (average per weekday)
Total - variability per weekday Jan. -> Oct.2011 180 160 140 120 100 80 60 40 20 0
2011_1 2011_2 2011_3
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2011_6 2011_7 2011_8 2011_9 2011_10 Average 2011
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Figure 5-18 - Average number of arrivals per weekday (participating airlines on RWY 25R/L; first 10 months of 2011).
Number of CDO marked arrivals (average per weekday)
CDO Marked - variability per weekday Jan. -> Oct 2011
2011_1 2011_2 2011_3
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Figure 5-19- Average number of CDO marked arrivals per weekday (participating airlines first 10 months of 2011).
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% CDO Marked - Variability per Weekday (LT) Jan. -> Oct. 2011 25%
2011_1 2011_2 2011_3 2011_4
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Average 2011
Figure 5-20 - Percentage of CDO marked arrivals per weekday (participating airlines first 10 months of 2011). 5.2.6
COMPARISON FOR RUNWAYS RUNWAYS 25R AND 25L
Figure 5-21 shows that the number of arrivals on runway 25L is much larger than the number of arrivals on runway 25R, with a monthly average of 2071 arrivals on RWY 25L and a monthly average of 1381 arrivals on RWY 25R. This is because runway 25R is not only used as an arrival runway but also is the most used departure runway, while RWY 25L is almost exclusively used as landing runway. When looking at the number of CDO marked arrivals per runway in Figure 5-22, the differences between the runways are smaller compared to the differences for the total amount of arrivals. This is because runway 25R is used relatively more during the calmer night hours, where also arrivals are more eligible to receive a CDOs approval. This is further demonstrated in Figure 5-23,where the highest numbers, expressed in percentages are for Runway 25R, with 10% of CDO-marked arrivals compared to 8% CDOmarked arrivals on RWY 25L.
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Total - per runway Jan. -> Oct. 2011
Averages - 25L: 2071 - 25R: 1381
3000 2500 2000 1500 1000 500 0
25L 25R
Figure 5-21 - Average number of arrivals for RWYs 25R & 25L (participating airlines; first 10 months of 2011).
CDO marked - per runway Jan. -> Oct. 2011
Averages - 25L: 174 - 25R: 135
250 200 150 100
25L_marked
50
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Figure 5-22 - Average number of CDO marked arrivals for RWYs 25R & 25L (participating airlines first 10 months of 2011).
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% CDO marked - per runway Jan. -> Oct. 2011
Averages - 25L: 8% - 25R: 10 %
14% 12% 10% 8% 6% 4% 2% 0%
% 25L %25R
Figure 5-23 - Percentages of CDO marked arrivals for RWYs 25R & 25L (participating airlines first 10 months of 2011).
5.2.7
FLIGHT LEVELS AT WHICH WHICH CDO IS APPROVED
Figure 5-24 shows the cumulative distribution for the flight levels at which the flight is CDOmarked. Most of the flights are marked at flight levels between FL60 andFL150.
Flight level when marked CDO - Cumulative distribution 1 Jul.2009 -> 31 Oct.2011 100.0% 90.0% 80.0% 70.0% 60.0% 50.0% 40.0% 30.0% 20.0% 10.0% 0.0% 0
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Flight level (FL)
Figure 5-24 - Cumulative distribution of flight levels for CDO-marked arrivals â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 79
250
B3 SESAR JU PROJECT Another presentation of the flight levels at which CDO is approved is given in the histogram of Figure 5-25. For this presentation flight levels are rounded to multiples of ten. The median flight level at which flights are marked CDO is FL100. Again it can be seen that most CDOs are marked for flight levels between FL60 and FL150.
Flight Level (FL)
Flight level when Marked CDO - Distribution 1 Jul.2009 -> 31 Oct.2011 250 230 220 210 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10
0% 0% 0% 0% 0% 0% 0% 1%
Median: FL 100 (Average: FL105)
2% 3% 5% 8% 11% 16% 19% 16% 11% 4% 3% 0% 0% 0% 0% 0% 0%
5%
10%
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Figure 5-25 - Distribution of flight levels for CDO-marked arrivals (1 Jul.2009 -31 Oct.2011). Figure 5-26 investigates the evolution over time of the average flight level at which CDOs are approved. There is a relatively high variation from month to month of the average flight level at which CDOs are approved. For the evolution over time however, though the linear regression line shows a small increase, there is no clear indication that the flight level at which CDO is approved changed significantly over time. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 80
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Average Flight Level (FL)
Flight Level when CDO marked - Evolution 120 115 110 105 100 95 90 85
Average Flight level at which CDO is approved = FL 105
07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 2009
2010
2011
Figure 5-26 - Evolution of the average FL at the moment arrivals are marked CDO. 5.2.8
TRACKMILES FROM TOUCHDOWN TOUCHDOWN AFTER CDO APPROVAL APPROVAL
The average number of trackmiles from touchdown at the moment of CDO marking is 36 NM. Typical numbers of trackmiles from touchdown range from around 20 NM to around 60 NM. The distribution is given in Figure 5-27 and Figure 5-28.
Distance from touchdown after CDO marked - Cumulative Distribution 1 Jul.2009 > 31 Oct.2011 100% 90% 80% 70% 60% 50%
Average number of trackmiles flown after CDO marked = 36 NM
40% 30% 20% 10% 0% 0
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Figure 5-27 - Cumulative distribution of distance from touchdown after CDO-mark (1 Jul.2009 -31 Oct.2011). â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 81
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Distance from touchdown after CDO-marked - Distribution 1 Jul.2009 -> 31 Oct.2011 50%
Average number of trackmiles flown after CDO marked = 36 NM
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Distance from touchdown (M)
Figure 5-28 - Distribution of distance from touchdown after CDO-mark (1 Jul.2009 -31 Oct.2011). The evolution over time of the average distance from touchdown is given in Figure 5-29. As for the flight levels, there is a relatively high variation from month to month of the average distance from touchdown for CDO-marked flights. For the evolution over time however, a linear regression line shows an increase. Mathematically this is due to the relative low average values in July 2009, October 2009, January 2010 and February 2010, but the reasons behind these low numbers could not be traced.
Average distance from Touchdown (NM)
Distance from touchdown after CDO marked - Evolution Average number of trackmiles flown after CDO marked = 36 NM
40 38 36 34 32 30
07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 2009
2010
2011
Figure 5-29 - Evolution of the average distance from touchdown after CDO-approval.
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B3 SESAR JU PROJECT 5.2.9
EFFECT OF THE CHANGE FROM WRITTEN TO CLICKED CLICKED CDOCDOMARKS
At the start of the trials in July 2009, distance from touchdown was estimated by the ATCO when approving CDO and written down on paper. Thanks to the B3-project a software development was made that allowed analysis of digital input of the ATCO on his CWP (Controller Working Position). This allowed in the course of November 2010 to replace the written input by digital input on the CWP. Distances are now calculated between the position of the arrival on the moment of digitally marking the flight “CDO-approved” and the moment of touchdown. The most important effect is that digitally marking CDOs is more convenient for the ATCO and thus helps to implement the CDO facilitation. Another advantage is that datacollection into a database is now automated, with a lower workload for post-processing as well as avoidance of human errors when interpreting the written forms. It has to be noted that the meaning of the distance information has slightly changed from the “ATCOs estimated distance from touchdown provided to the pilot by ATC”, to “system calculation of the distance from touchdown”. From the data point of view the effect is that for the written data, ATCOs used merely rounded values. Today, thanks to the digital marking, finer values are obtained. This is illustrated in the Figure 5-30 and Figure 5-31 below, respectively for flight levels at which CDOs are marked and for distances flown after CDO-marking.
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Flight Levels at which CDOs are marked 1 Jul.2009 - 31 Oct.2011 120
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Figure 5-30 - Effect of switching to marking of flights on the CWP for flight levels .
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B3 SESAR JU PROJECT Distance from touchdown after CDO-approval 1 Jul.2009 -> 31 Oct.2011 200 180
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Figure 5-31 - Effect of switching to marking of flights on the CWP for distance from touchdown. 5.2.10
SUMMARY AND CONCLUSION CONCLUSION FOR POINT 5.2
In total for 5.407 arrivals a CDO was facilitated by Brussels APP, from which 3094 considered as B3-trials. After a fallback in 2010, CDO facilitation was actively resumed during Phase II of the B3-project. For the period from 1 January 2011 until 31 October 2011 the total amount of CDOs facilitated was 9% of the a total amount of arrivals by participating airlines on the runways 25R/L. The amounts of CDOs marked vary largely from day to day, from week to week and from hour to hour. Two clear and recurrent reasons for the variability are the amount of traffic and the runways that were in use. The higher the traffic, the lower the percentage of CDOs. The trials were only performed on runways 25R and 25L. Therefore on those times when these runways are not used, there is no potential for trialled flights. Flight levels at which the CDO-facilitation starts are variable. The median value is FL100. More than 90% of the flights is marked at flight levels between FL60 and FL150.
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B3 SESAR JU PROJECT 5.3
CDOCDO-PERFORMANCE PERFORMANCE (EFICAT(EFICAT-ANALYSIS) – APRIL & MAY 2011
The current section provides the results of the EFICAT analysis. Information on the tool and preparation of the datasets can be found in Chapter 4, more specifically in the points 4.2.4 and 4.3.2. 5.3.1 5.3.1.1
CDOCDO-CRITERIA USED PARAMETER SETTING
The following criteria were used to identify a CDO in the EFICAT-tool, in which solely radarinformation is available: -
Maximum 1 segment of level flight below the “Above/Below Altitude Parameter”. The Above/Below Atlitude Parameter was consecutively set to FL60, FL80 and FL100. Level flight max. 2.5 NM Level flight was defined in the EFICAT tool with the following parameters set: - Level tolerance = 200 ft/min - Minimum Time for Level Plots = 20 sec , this corresponds to: o 0.7 NM @ 250 kts o 0.6 NM @ 210 kts
All the results are calculated for radar data from the “Above/Below Altitude Parameter” (FL100, FL80 or FL60)down to 1500 ft. The parameter settings used in EFICAT are shown in the Figure 5-32 below.
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Figure 5-32 - Parameters set in EFICAT to analyseradardata.
5.3.1.2
CLASSIFICATION IN FOUR FO GROUPS OF CDO-PERFORMANCE PERFORMANCE
After the EFICAT analysis each arrival is classified cla either as - No CDO = flights that are not CDO below FL60 - CDO from FL60 = flights that are CDO from FL60, but not from FL80 - CDO from FL80 = flights that are CDO from FL80, but not from FL100 - CDO from FL100 Examples for each of this four categories are ar shown below.
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Figure 5-33 - Examples for “No CDO”.
Figure 5-34 - Examples for “CDO FL60”.
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Figure 5-35 - Example for “CDO FL80”.
Figure 5-36 - Examples for “CDO FL100”.
5.3.1.3
DATA SAMPLE FOR STATISTICS IN SECTION 5.3
The EFICAT analysis is performed on data for the months of April and May 2011. All statistics in section 5.3 refer to this period. The EFICAT analysis is performed for all arrivals at EBBR and therefore includes both participating and non-participating airlines, arrivals on all the EBBR-runways and both marked and not-marked arrivals.
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B3 SESAR JU PROJECT Remark for EFICAT analysis for June and July 2011: Brussels Airlines provided FDM-data for analysis in the B3-project. Most of these FDM-data are for the months April and May 2011. However some are for June and July 2011. For days in June and July where FDM-data were made available by Brussels Airlines, also the EFICAT analysis was run. The EFICAT-analysis for June and July 2011 however are only used in combination with results of the analysis of the FDM-data and are not included in the statistics in section 6.3. 5.3.2 5.3.2.1
CDOCDO-PERFORMANCE PERFORMANCE (PROFILES) ALL AIRLINES, ALL RUNWAYS
As shown in the figure below, a total of 55% of all arrivals follows a continuous descent profile below FL100, another 4% follows a Continuous Descent profile from FL80 and 7% follows a continuous descent profile from FL60. Only 34 % of the arrivals does not follow a continuous descent profile.
CDO estimation by EFICAT All arrivals - All Rwy's
CDO FL100 10334 55% No CDO 6313 34%
CDO FL 60 1387 7%
CDO FL 80 697 4%
Figure 5-37 - CDO estimation by EFICAT, all arrivals, all runways.
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ALL AIRLINES , RUNWAYS 25R/L
The trials are only performed on runways 25R/L. Therefore the figure below shows the % of continuous descent profiles on runways 25R & 25L only. It can be seen that the continuous descent performance is better on the runways 25R/25L compared to the previous figures for all arrivals. The statistic for 25R/L contains both marked and not marked arrivals.
CDO estimation by EFICAT All arrivals - RWYs 25L/R
CDO FL100 8882 61% No CDO 4286 29% CDO FL 60 931 6%
CDO FL 80 604 4%
Figure 5-38 - CDO estimation by EFICAT, all arrivals, only runways 25R/L.
5.3.2.3
MARKED VERSUS NOT MARKED FOR ALL AIRLINES
The figure below compares the profiles for marked flights with profiles for non-marked flights. For the non-marked flights 59% flies a continuous descent profile from FL100. For marked flights this % goes up to 82%. This is an increase with 29 % ((82-59)/82) ! The number of arrivals that does not perform a CDO at all is halved from 30% for non-marked flights to 16 % for marked flights. Also remarkable is that for marked flights almost all arrivals are either CDO from FL100 or no CDO, with almost no arrivals with a CDO starting only at FL60 or FL80. For the non-marked flights respectively 4% peforms a CDO from FL80 and 7% performs a CDO from FL60.
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B3 SESAR JU PROJECT CDO estimation by EFICAT All airlines - RWYs 25L/R Not Marked
CDO estimation by EFICAT Participating airlines - RWYs 25L/R Marked
CDO FL100 8356 59% No CDO 4180 30% CDO FL 60 925 7%
CDO FL 80 598 4%
CDO FL 60 6 1%
No CDO 106 16%
CDO FL100 526 82%
CDO FL 80 6 1%
Figure 5-39 - Comparison of CDO-performance estimated by EFICAT for marked flights from participating airlines and not marked flights for all airlines.
5.3.2.4
MARKED VERSUS NOT MARKED FOR PARTICIPATING AIRLINES
It can be seen from Figure 5-39 and Figure 5-40 that the CDO-performance even for not marked flights is better for airlines participating to the trials compared to the total group of airlines. A potential reason is that pilots from participating airlines give more attention to optimising their descent profile, either because of company policy, either thanks to the increased awareness via the B3-trials. Evidence for the latter is that some controllers reported that pilots seem to perform more CDOs even when not given explicit approval. Other potential explication could be that the four most frequent users of EBBR participate in the trials and thus their pilots might be more familiar with the airport and thus can better optimise their profile. As no historical comparable datasets from before the trials is available, the above potential explications cannot be checked. Also for the participating airlines, the marked flights show a clearly better CDO-performance than the not marked flights. 82 % of the marked flights has a CDO-profile from FL100 in EFICAT, compared to 65% of the not marked flights. This is an increase with 21% ((8265)/82). For participating airlines, the percentage of arrivals that have no CDO profile at all reduces from 26% for non marked flights to 16 % for marked flights. This is a reduction with 38 % ((26-16)/26).
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B3 SESAR JU PROJECT CDO estimation by EFICAT Participating airlines - 25R/L Not Marked
No CDO 1536 26%
CDO FL100 3844 65%
CDO estimation by EFICAT Participating airlines - 25R/L Marked
No CDO 106 16%
CDO FL 60 6 1%
CDO FL100 526 82%
CDO FL 80 6 1%
CDO FL 60 274 5% CDO FL 80 241 4%
Figure 5-40 - Comparison of CDO-performance estimated by EFICAT for marked flights from participating airlines with not marked flights for all airlines. 5.3.2.5
COMPARISON FOR RUNWAY 25 R & 25L
Figure 5-41 shows the comparison between runways 25R and 25L of the CDO-performance for marked flights. The CDO performance is somewhat better for runway 25L compared to runway 25R. This is in the line of expectations because the proportion of downwind arrivals is larger for RWY 25R as for RWY 25L.
CDO estimation by EFICAT Participating airlines - 25R Marked
CDO FL 60 2 1%
No CDO 57 18%
CDO estimation by EFICAT Participating airlines - 25L Marked
CDO FL100 241 79% CDO FL 60 4 1%
No CDO 49 15%
CDO FL100 285 84%
CDO FL 80 6 2%
Figure 5-41 - Comparison of CDO-performance estimated by EFICAT for Runways 25R and 25L. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 93
B3 SESAR JU PROJECT 5.3.3
CDOCDO-PERFORMANCE (PROFILES) (PROFILES) FOCUS ON BRUSSELS AIRLINES
The figures in this point provide the EFICAT CDO-performance per aircraft type for arrivals with callsign “BEL”. When interpreting the data it should be born in mind that the number of flights can hugely differ per aircraft type. Figure 5-42 below provides an overview of the number of flights per aircraft type that operated under the BEL-callsign in the dataset for April and May 2011. Figure 5-43 gives the number of marked BEL-flights in the datasampleanalysed with EFICAT. From the latter figure it is clear that average for marked flights are relevant for the Airbusses, the Boeings 733 and 734 and the Avros, but less for DH8D, the Embraers and the other Boeings. These aircraft types are therefore not included in all of the figures that follow.
BEL - CDO estimation by EFICAT All Arrivals - All RWY's 2000 1500 No CDO 1000
CDO FL 60 CDO FL 80
500
CDO FL100 0
Figure 5-42 - EFICAT CDO estimation in absolute values – all runways, all arrivals with BEL-callsign.
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Marked BEL arrivals - Per Aircraft type in April- May 2011 dataset analysed with EFICAT Number of marked flights
140 120 100 80 60 40
114 89 45
20 0
131
8
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25 4
1
A319 A320 A333 B733 B734 DH8D E145 RJ1H RJ85 Figure 5-43 - Number of marked BEL-arrivals per aircraft type in the April-May 2011 dataset analysed with EFICAT. Figure 5-44 below gives the overall CDO-performance for BEL-flights. The Avros and the Boeings have the highest overall CDO performance, with more than 60% of CDOs below FL100 and 30% or less with no CDO. The Airbus 333 has, with 39%, the lowest percentage of CDOs-profiles below FL100, as well as with 45% the highest number of non CDO profiles.
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BEL - CDO estimation by EFICAT All arrivals - All RWY's
37% 5% 7%
14%
51%
62%
61%
63%
50%
20%
5% 3%
2%
48%
30%
27%
40%
5% 3%
65%
9% 2%
39%
50%
8% 1%
1%
25%
60%
16% 5% 5%
66%
6% 5%
70%
30%
26% 45%
41%
80%
41%
90%
21%
100%
10% 0% A319 A320 A333 B733 B734 DH8D E145 RJ1H RJ85
No CDO
CDO FL 60
CDO FL 80
CDO FL100
Figure 5-44 - CDO-performance per aircraft type estimated by EFICAT for Brussels Airlines arrivals on all runways. While Figure 5-44 above provides numbers of the total amount of arrivals, the Figure 5-45 focuses on all arrivals on the runways in the trials, 25R and 25L. For 25R/L the CDO performance is clearly better when looking only at runways 25R/L.
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BEL - CDO estimation by EFICAT All arrivals - RWY's 25R/L 22%
36%
15%
3% 3%
3% 3%
72%
7% 1%
21%
50%
8% 2%
4% 5%
2%
74%
60%
12% 3% 6%
70%
28%
39%
38%
80%
37%
90%
25%
100%
6% 8%
15%
63%
66%
50%
20%
44%
54%
53%
30%
71%
2%
40%
10% 0% A319 A320 A333 B733 B734 DH8D E145 RJ1H RJ85
No CDO
CDO FL 60
CDO FL 80
CDO FL100
Figure 5-45 - CDO-performance per aircraft type estimated by EFICAT for Brussels Airlines arrivals on runways 25R and 25L. Figure 5-46 compares side by side the CDO-performance for marked an not marked arrivals on the runways 25R/L. For each of the individual aircraft types, the CDO-performance is clearly better for marked flights compared to non-marked flights. For Avros, marked flights have respectively 84% and 88% of CDO-profiles compared to 73% and 71% for non marked flight. For DH8D and E145 100 % of the marked flights have a CDO-profile below FL100. However ref. figure 6.30 there are only 4 marked DH8D and 1 marked E145 in the analysed dataset. For the Airbus 319 the % of CDO-profiles below FL100 increases from 52% for non marked â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 97
B3 SESAR JU PROJECT flights to 63 % for marked flights - an increase with 21% ((63-52)/52). For the Airbus 333 the % of CDO profiles below FL100 increases from 42% for non marked flights to 60% for marked flights - an increase with 43 % ((60-42)/42).
30%
15%
12% 88%
100%
60%
88%
40%
63%
73%
50%
100%
70% 60%
50%
84%
8%
18%
32%
1%
82%
13% 34%
23%
16% 70%
61%
90% 80%
8%
16%
65%
49%
20%
52%
30%
3% 3%
6%
2%
40%
3% 3%
71%
8% 2%
2%
42%
50%
9% 2%
4% 6%
22%
70% 60%
12% 3% 7%
36%
40%
41%
80%
37%
90%
29%
100%
25%
100%
20%
BEL - CDO estimation by EFICAT Marked - 25R/L
80%
BEL - CDO estimation by EFICAT Not marked - 25R/L
20%
10%
10%
0%
0% A319 A320 A333 B733 B734 DH8D E145 RJ1H RJ85
No CDO
CDO FL 60
CDO FL 80
A319 A320 A333 B733 B734 DH8D E145 RJ1H RJ85
CDO FL100
No CDO
CDO FL 60
CDO FL 80
CDO FL100
Figure 5-46 - Comparision of CDO-performance estimated by EFICAT for marked and not marked arrivals - per aircraft type for Brussels Airlines arrivals on runways 25R and 25L. 5.3.4
FUEL AND CO2 ESTIMATIONS ESTIMATIONS WITH EFICAT
The EFICAT tool only has available radar data to estimate fuel use and CO2-emissions. Based on the radar data and in combination with BADA (Base of Aircraft Data) reference datasets per aircraft type, the EFICAT-tool makes estimations of the fuel used and CO2 produced. Fuel data for a limited amount of A319 and A333 is also made available for the B3-project by Brussels Airlines. These data are real fuel measurements and thus are more reliable. These more reliable results are included in section 5.5 and show a fuel difference between marked and not-marked flight of +/- 50 kg for A319 and +/- 100 kg for A333. Fuel and Co2-estimations made with the EFICAT tool are presented in the Figure 5-47, Figure 5-48and Figure 5-49. Figure 5-47 and Figure 5-48 show the difference in respectively â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 98
B3 SESAR JU PROJECT average fuel and average CO2 for marked and not marked flights for all participating airlines. Except for A30B, the average fuel and CO2 estimates for marked flights are systematically lower compared to not marked flights. The largest difference, an average difference of 125 kg fuel/393 kg CO2 is for B744. As a remark it can be said that the dataset contains 5 marked and 47 not marked B744 with a rather continuous range of fuel values, which provides confidence that no extreme data cause the big difference, but rather the fact that it is the largest aircraft analysed.
Fuel difference (FL100 - 1500ft) between non-marked and marked arrs. (kg)
EFICAT Fuel estimation (FL100 - 1500 ft) Participating airlines (min. 5 marked per Aicraft type) Difference between non-marked and marked 140
125 120 100 80 60 40
22 15
20 0 -20
-5
27
26 19
17
14 3
8
14
16
12
A30B A319 A320 A333 B733 B734 B735 B737 B738 B744 B752 RJ1H RJ85 Grand Total
Figure 5-47 - Average absolute difference in EFICAT fuel estimation for marked and not marked flights â&#x20AC;&#x201C; per aircraft type for all participating airlines.
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CO2 difference (FL100 - 1500ft) between non-marked and marked arrs. (kg)
EFICAT CO2 estimation (FL100 - 1500 ft) Participating airlines (min. 5 marked per Aicraft type) Difference between non-marked and marked 450
393
400 350 300 250 200 150 100
68 47
50 0 -50
-15
86
82 60
52
45 10
24
44
51
37
A30B A319 A320 A333 B733 B734 B735 B737 B738 B744 B752 RJ1H RJ85 Grand Total
Figure 5-48 - Average absolute difference in EFICAT CO2 estimation for marked and not marked flights â&#x20AC;&#x201C; per aircraft type for all participating airlines. Figure 5-49 and Figure 5-50 below provide the same types of graph, but this time for only the Brussels Airlines flights. As a global average for Brussels Airlines, EFICAT calculates a difference per flight of 16 kg/ for marked versus not marked flights. For two of these aircraft types: A319 and A333, also real fuel data were received from Brussels airlines. From these FDM-data the difference between marked and non marked flights is clearly larger with +/- 50 kg of difference for A319 and +/- 100 kg difference for A333. So at least for those two aircraft types, the EFICAT estimates of the difference in fuel use is at the lower side.
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Fuel difference (FL100 - 1500ft) between non-marked and marked arrs. (kg)
EFICAT Fuel estimation (FL100 - 1500 ft) Brussels Airlines (min. 5 marked per Aircraft type) Difference between non-marked and marked 30
27
26
24 19
20
17
16
B734
RJ1H
16
15
10
0
A319
A320
A333
B733
RJ85
Grand Total
Figure 5-49 - Average absolute difference in EFICAT fuel estimation for marked and not marked flights – per aircraft type for Brussels Airlines.
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CO2 difference (FL100 - 1500ft) between non-marked and marked arrs. (kg)
EFICAT CO2 estimation (FL100 - 1500 ft) Brussels Airlines (min. 5 marked per Aircraft type) Difference between non-marked and marked 100
86
90
82
75
80 70
59
60 50
53
52
B734
RJ1H
50
47
40 30 20 10 0
A319
A320
A333
B733
RJ85
Grand Total
Figure 5-50 - Average absolute difference in EFICAT CO2 estimation for marked and not marked flights – per aircraft type for Brussels Airlines. Figure 5-51 and Figure 5-52 below also show the percentage differences in respectively fuel and CO2 between marked and not marked flights for Brussels Airlines’ flights. Marked flights compared to not marked flight show, based on EFICAT estimations, differences between 7% and 19% of fuel and CO2 use.
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Fuel difference (FL100 - 1500ft) between non-marked and marked arrs. (kg)
EFICAT Fuel estimation (FL100 - 1500 ft) Brussels Airlines (min. 5 marked per Aircraft type) Difference between non-marked and marked 20%
19%
19%
15% 11%
11% 10%
11%
10%
10% 7% 5%
0% A319
A320
A333
B733
B734
RJ1H
RJ85
Grand Total
Figure 5-51 - Average percentage difference in EFICAT fuel estimation for marked and not marked flights â&#x20AC;&#x201C; per aircraft type for Brussels Airlines.
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CO2 difference (FL100 - 1500ft) between non-marked and marked arrs. (kg)
EFICAT CO2 estimation (FL100 - 1500 ft) Brussels Airlines (min. 5 marked per Aircraft type) Difference between non-marked and marked 20%
19%
19%
15%
11%
11% 10%
11%
10%
10%
7% 5%
0%
A319
A320
A333
B733
B734
RJ1H
RJ85
Grand Total
Figure 5-52 - Average percentage difference in EFICAT CO2 estimation for marked and not marked flights – per aircraft type for Brussels Airlines.
5.3.5
FUEL AND CO2 ESTIMATIONS ESTIMATIONS WITH EFICAT COMPARED COMPARED TO FDMFDMFUEL DATA
Figure 5-53 shows for each Airbus 319 flight with FDM-data provided, the difference between the fuel estimation with the EFICAT-tool and the real fuel . Estimations by the EFICAT-tool are relatively good for A319. For CDO flights the differences are equally spread above and below zero. For non CDO flights EFICAT tends to underestimate the fuel use.
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Difference of EFICAT fuel estimations with FDM-data A319 60
40
20
0 0
4
-20
-40
-60 CDO100
CDO60
No_CDO
Figure 5-53 - Difference of Eficat fuel estimation compared to FDM fuel data for Airbus 319. The next figure shows for each Airbus 333 with FDM-data provided, the difference between the fuel estimation with the EFICAT-tool and the real fuel based on FDM-data. It can be seen that for A333, EFICAT overestimates the fuel used. Overestimations are larger for A333 that fly CDO-profiles compared to A333 that fly non CDO profiles.
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Difference of EFICAT fuel estimations with FDM-data A333 250 200 150 100 50 0 0
4
-50 -100 -150 -200 -250 CDO100
CDO60
No CDO
Figure 5-54 - Difference of Eficat fuel estimation compared to FDM fuel data for Airbus 330.
5.3.6
SUMMARY SUMMARY AND CONCLUSION FOR FOR POINT 5.3 5.3
For the analysis of radartracks with the Eurocontrol EFICAT tool, an arrival was considered CDO if there was only one segment of level flight, with a maximum length of 2.5 NM. The analysis was done from FL60, from FL80 and from FL100, each time until 1500 ft. Radardata were analysed for all arrivals at Brussels Airport in the months of April and May 2011, allowing comparisons for CDO-marked and not CDO marked flights. A first observation is the relatively high amount of CDO-profiles: 66% of all arrivals in April and May 2011 had a â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 106
B3 SESAR JU PROJECT CDO-profile below FL60. 55% even had a CDO-profile below FL100. These numbers are for the total of all airlines, and for all runways. The amount of CDO-profiles on the runways 25R and 25L for marked flights is 82%. This is a significant increase with regard to not-marked flights for which 59% shows CDO-profiles below FL100. Exact fuel figures can only origin from airlines. As the B3-project has shown, it asks considerable effort to extract and analyse these data. Also, except in projects like B3, ANSPs and Airports do not have access to the airlinesâ&#x20AC;&#x2122; fuel data. Therefore the Eurocontrol EFICAT tool provides fuel estimations based on only radar-data. Fuel estimations with EFICAT show systematically fuel gains for marked flights compared to not marked flights, indicating that fuel can be saved for CDO-facilitated flights. The fuel gains vary widely from aircraft type to aircraft type from around zero to 125 kg for B744. One of the actions of the B3-project was to compare fuel estimations from the EFICAT tool with real fuel data, for 2 aircraft types. For these two aircraft types the EFICAT-tool seemed to under-estimate the real fuel gains.
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B3 SESAR JU PROJECT 5.4
RESULTS OF CDO TROUBLE TROUBLE REPORT (ATCOS).
Vertical profile. Traffic routeing via FLORA (CTA East) is overflying Beauvechain TMA and thus is restricted in altitude. This altitude restriction should not be an issue when performing a CDO of +/- 3° descent angle. At the start of the project CDO Trouble Reports were filed regarding the incorrect execution of CDOs, especially in respect of the vertical profile. This led to an increase of ATCOs interventions to prevent airspace infringements. By issuing ‘INITIAL’ descend clearances, this problem was solved and no more Trouble Reports regarding this issue were filed. Speed. A second issue which was reported in the CDO Trouble Reports was that pilots were not adhering to the published speeds. It was observed that some pilots maintained a relatively high speed and used a portion of level flight in low altitudes to reduce the speed. Airlines were asked to brief pilots to adhere to the published speeds. A third identified issue was regarding the correct speed “phraseology” and the use of it.All ATCOs were briefed on the correct phraseology. •
Avoid the use of “High speed approved”
•
The correct phraseology is “No ATC speed restriction”
Remark: this does not apply to situations where speed control is needed for sequencing.
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B3 SESAR JU PROJECT 5.5
RESULTS FROM FDMFDM-ANALYSIS
5.5.1
EXAMPLES.
Airbus A330-300 – Early descent with several level-off parts. (Ref. A333_01).
Figure 5-55 - Airbus A330-300 – Early descent with several level-off parts. This flight initiated its descent about 108 NM prior to the TOD corresponding with the reference descent path. Intermediate level-offs were performed at FL340, FL200 and finally at 3000 ft altitude. The aircraft, although coming close to it at FL200, remained below the reference profile during its entire descent. The flight did not receive a CDO-approval.
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Figure 5-56 - Airbus A330-300 – Early descent with several level-off parts - Fuel Burn. Comparison of the flown profile against the reference descent profile revealed a 460.2 kg fuel penalty and an extra flight time of 3.9 minutes between TOD and a descent fix defined at 1500 ft above runway threshold. Wind below FL200 proved to have no significant impact on the overall profile. Detailed examination of the descent path below FL100 revealed a level portion of about 10 NM.
Figure 5-57 - Airbus A330-300 – Early descent with several level-off parts - Fuel Burn low altitude. – Phase 2 Version 4.2 - 15/02/2012 - Page 110
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This level portion appeared to account for more than 200 kg extra fuel burn in comparison with the fuel burn figure when flying the reference profile. Note the perfect parallelism of both fuel burn figures, which confirms the validity of the reference profile fuel burn. The level portion at FL200 accounted for another 200 kg extra fuel burn. Airbus A330-300 – Descent initiated slightly before the reference profile TOD. (Ref. A333_03).
Figure 5-58 - Airbus A330-300 – Descent initiated slightly before the reference profile TOD. A reduced rate of descent was applied until reaching the profiles descent at about FL380. The profile was followed until FL150. Then, the flight crew opted for a descent below the reference profile until a level off portion brought the aircraft back on this profile. Later on, the aircraft again descended below its reference profile. The flight did not receive a CDO-approval.
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Figure 5-59 - Airbus A330-300 – Descent initiated slightly before the reference profile TOD - Fuel Burn. Comparison of the flown profile against the reference descent profile revealed a 137.8 kg fuel penalty and an extra flight time of 0.6 minutes between TOD and a descent fix defined at 1500 ft above runway threshold. A FDM-anomaly on this particular aircraft prevented us from calculating and plotting the ‘air-distance’ in order to evaluate the possible impact of wind.
Figure 5-60 - Airbus A330-300 – Descent initiated slightly before the reference profile TOD - Fuel Burn low altitude.
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B3 SESAR JU PROJECT The 8 NM long flat portion of the descent at FL60 accounted for an extra fuel burn of around 100 kg. This level-off was used to reduce speed to 250 KIAS. It is not clear why the flight crew elected to accelerate again, and by doing so, drifted again below the reference profile. Once more, please note the perfect parallel between both fuel burn figures.
Airbus A330-300 – Adherence to reference profile and speed schedule. (Ref. A333_06).
Figure 5-61 - Airbus A330-300 – Adherence to reference profile and speed schedule. For this flight, the crew apparently was forced to initiate the descent some 50 NM prior to TOD, and elected to descent at 1000 fpm until reaching (more or less) the reference descent path. From that very moment, and despite the fact that no CDO-approval was delivered, a continuous descent was flown until intercept of the glideslope.
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Figure 5-62 - Airbus A330-300 â&#x20AC;&#x201C; Adherence to reference profile and speed scheduleFuel Burn. This conduct of the descent even resulted in a 3.2 kg fuel burn gain in comparison with the reference profile. The 1.1 minutes time penalty probably results from the descent being flown at 290 KIAS i.s.o 300kt. Note the deceleration to 250 KIAS below FL100.
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B3 SESAR JU PROJECT Airbus A330-300 – Descent above the reference profile. (Ref. A333_22).
Figure 5-63 - Airbus A330-300 – Descent above the reference profile. In this flight, the descent was initiated well beyond the reference profile TOD, and remained above this reference profile. A level-off at FL220, probably forced, even aggravated this situation. In order to retrieve a ‘normal’ descent profile, extensive use of the spoilers had to be made. The flight received a CDO-approval at FL124, some 40 NM prior to touchdown. The aircraft was well above the reference profile at that time.
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Figure 5-64 - Airbus A330-300 – Descent above the reference profile – Fuel Burn. Late initiation of the descent and the intermediate level-off at FL220 accounted for more than 250 kg extra fuel burn.
Figure 5-65 - Airbus A330-300 – Descent above the reference profile – Fuel Burn Low Altitude. – Phase 2 Version 4.2 - 15/02/2012 - Page 116
B3 SESAR JU PROJECT The deceleration to 250 KIAS was initiated slightly late, which, combined with a fairly flat descent segment of 8 NM length, may have h led to a 3 NM level-off off at 2000 ft, resulting in a 80-100 kg extra fuel burn. 5.5.2
RECURRENT OBSERVATIONS OBSERVATIONS
1. Airplane FMGS As previously mentioned, the FMGS computes the optimum target speed (ECONSPD/MACH) as a function of: Cost index (CI) Cruise flight level el (CRZ FL) Gross weight (GW) Wind and temperature models Performance factor. Based on the flight observed and the crew debriefing given, it is obvious that the FMGS module works perfectly as advertised, advertise with restrictions. a. The FCOM, as shown in the paragraphs parag above, will calculate an optimum descent without any level portion allocated for speed reduction.
66 - Airbus A319 – FCOM Descent Profile. Figure 5-66
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B3 SESAR JU PROJECT b. The FMGS will do dynamic planning and has a level portion of flight to allow for speed reduction and initial configuration. The dynamic planning will allow the level portion to variate in length depending on the aircraft speed. The higher the speed, the longer the level portion will be.
Figure 5-67 - Airbus A319 â&#x20AC;&#x201C; FCOM versus FMGS profiles. Ass observed on the above graph (Figure 1.33) the FMGS takes into account three factors: 1) Non obstent what the FCOM (used for planning) gives; the FMGS does not provide provide a deceleration during descent. 2) In standard conditions the FMGS will provide a deceleration segment between 1.8 to 2nm for deceleration from 250kts to 220kts (initial approach segment for Flap/Slat extension) 3) This level segment is dynamic, the higher the speed the longer the segment. This is consistent with high Cost Index to allow safe reduction. This is of course correct provided the crew has entered descent winds. Otherwise the FMGS will extrapolate between the actual wind during descent and the wind entered in the PERF APPROACH PAGE by the crew. Any incorrect or absence of data could induce invalid profiles causing steeper or shallower approaches. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 118
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2. Pilot Flying Technics a. Standard approaches using FMGS guidance will show a slightly less than optimum profile. But higher profile could induce late speed reduction with drag devices (speed brakes, landing gear extension, etc.) There for in normal operation the 40kg lost in the level portion have to be considered as the normal fuel consumption during final descent. b. However, such as described in the manufacturer manuals Low Drag Low Noise (Boeing) Low Power Low Drag (Airbus) It is possible depending on company regulation and adequate weather, for the pilot to adjust his flight to minimize any configuration change provided he be established on profile in landing configuration with thrust set latest at 1000ft or 500ft Above Ground Level (AGL) (see company regulations) c. Adding FMGS information and Low Power Low Drag technic can bring the aircraft exactly on the FCOM profile while remaining safe in all aspects of the flight. This requires pilot techniques that are part of the basic flying skills but tend to be less trained over the years. d. Knowing the importance of the impact of a proper descent to be executed at all times and that the pilot, using all the tools in his possession, can perform as the manufacturer advises in the FCOM, it is the responsibility of each company to brief and train the pilots to the maximum extent possible. Every company is responsible to set the safety standards as high as possible and in the same time train their pilots to achieve CDOs as much as possible. This is where most of the work started within Brussels Airlines: changing the mentalities by making the pilots aware of the savings in fuel (and by such in CO2 emissions) that could be made on a daily basis. Even if all flights cannot perform an optimum descent from TOD, it is possible with partial CDO to make for what was lost on other flights due to external factors (traffic congestion, bad weather, etc.) e. Examples below will demonstrate various situations where less than optimal resources where used. The causes can by various and cannot be deduced from the graphs below. These deviations can be caused weather, ATC, aircraft restrictions. The aim is not to blame but to learn.
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B3 SESAR JU PROJECT General tendency to remain below the reference (FMS) descent profile. Example: A319_03
Figure 5-68 - Airbus A319 – below profile. Example: 333_05
Figure 5-69 - Airbus 330 – below profile.
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Inappropriate(?) use of speedbrakes. Example: A319_10
Figure 5-70 - Airbus 319 – use of speedbrake profile.
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B3 SESAR JU PROJECT High speed below FL100. Example: A319_13
Figure 5-71 - Airbus 319 – high speed below 10.000ft profile. Example: A319_19
Figure 5-72 - Airbus 319 – high speed below 10.000ft profile (2).
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B3 SESAR JU PROJECT 5.5.3
OVERVIEW OF RESULTS.
The following pages contain the tabulated results of the detailed fuel burn analysis of 56 descents into Brussels Airport. All descents were flown using either Airbus A319 or Airbus A330-300 (A333) aircraft. A mix of flights with and without explicit CDO-approval were considered:
Aircraft Type
Explicit CDO-approval
Without CDO-approval
Airbus A319
16
17
Airbus A330-300
12
11
Legend and meaning of the data used in following Tables: REF-field: Column 1:
Unique reference for each flight. Detailed graphs available for each flight
Column 2:
Tail number of the aircraft which performed the descent
CDO approval info: Column 1: Indicates whether or not a CDO-approval was issued. “Marked” means CDO. Column 2:
Time of day of the issuance of the clearance.
Column 3:
Duration of the approved CDO-portion of the descent.
Column 4:
Altitude (FL – flight level) at which the CDO-approval was issued.
Column 5:
Remaining distance (NM) to touchdown at issuance of CDO-approval.
EFICAT-field: Column 1: Indicates whether or not the descent path between FL60 and 1.500 ft AGL was considered to be a CDO by the Eurocontrol EFICAT-tool. Column 2: Idem for the descent between FL80 and 1.500 ft AGL. Column 3: Idem for the descent between FL100 and 1.500 ft AGL.
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B3 SESAR JU PROJECT Results based on FDM data: Column 1: Indicates an eastbound (KERKY) or westbound (FLO) approach into either RWY25L or RWY25R at Brussels Airport. Column 2: Column 3: Column 4:
Fuel burn (kg) during the descent from FL60 down to 1500 ft AGL. Idem column 2 from FL80 down to 1.500 ft AGL. Idem column 2 from FL100 down to 1.500 ft AGL.
Column 5:
Descent initiation point versus the reference profile top-of-descent (TOD). E = early descent (before the reference TOD) A = ‘at’ the calculated reference TOD L = late descent (after the reference TOD)
Column 6: FL200.
Actual descent profile versus reference descent profile between FL300 and
Column 7: Column 8:
A = above the profile O = on the profile B = below the profile Idem column 6 between FL200 and FL100. Idem column 6 below FL100.
Column 9-11: Altitude (feet) of intermediate level-off segment(s) if any observed. Column 12: Column 13: Column 14:
Speed brake use between FL300 and FL200. Idem column 12 between FL200 and FL100. Idem column 12 below FL100.
Column 15: Column 16:
Average indicated air speed (KIAS) above FL100. Idem column 15 below FL100.
Airbus A319. Ten flights proceed along an eastbound pattern; the remainder (23) follow a westbound pattern into the landing runway(s). Note that only one descent path is above the reference profile below FL100; three are more or less on the reference profile. The overwhelming majority is clearly below the reference profile. Although not known to which extent (the FDM-data do not record the details), 9 flights make use of the speed brake below FL100. For all the analysed descents we recorded/calculated following fuel burn (kg):
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B3 SESAR JU PROJECT FL60-1500
FL80-1500
FL100-1500
Minimum value
48.1
56.6
66.8
Maximum value
200.0
219.0
243.5
Median value
85.1
103.6
119.4
Average value
90.7
115.0
133.9
Standard deviation
33.8
41.2
44.0
Table 5-1 - Airbus A319 – Overview of all flights – Fuel Burn. For 6 out of the 16 flights with an explicit CDO-approval delivered, the EFICAT-tool does not consider the flown descent below FL100 to be compatible with a “CDO”. This finding is confirmed by the FDM-data analysis. For all descents with a CDO-approval, we have following fuel burn (kg): Altitude
Track miles
FL60-1500
FL80-1500
FL100-1500
Minimum value
78.0
29.0
48.6
56.6
66.8
Maximum value
143.0
46.0
95.8
115.8
130.5
Median value
109.5
39.5
73.2
93.4
115.7
Average value
110.5
39.2
72.2
89.1
107.2
Standard deviation
13.7
4.2
14.7
16.6
19.1
Table 5-2 - Airbus A319 – Overview of all flights with CDO-approval – Fuel Burn. For 8 out of the 17 flights which did not receive an explicit CDO-approval, the EFICAT tool nevertheless considers the flown profile below FL100 to be compatible with a CDO-profile. For all descents without a CDO-approval, we have following fuel burn (kg):
FL60-1500
FL80-1500
FL100-1500
Minimum value
48.1
61.1
73.7
Maximum value
200.0
219.0
243.5
Median value
101.5
138.0
163.0
Average value
108.1
139.4
159.0
Standard deviation
37.7
42.8
46.3
Table 5-3 - Airbus A319 – Overview of all flights without CDO-approval - Fuel Burn. – Phase 2 Version 4.2 - 15/02/2012 - Page 125
B3 SESAR JU PROJECT Comparison of the CDO “Marked” against “Not_Marked” flights leads to following results (kg):
FL60-1500
FL80-1500
FL100-1500
Median value
-28.3
-44.6
-47.4
Average value
-35.9
-50.3
-51.8
Conclusions: The conduct of a CDO-approach with an Airbus A319 single-aisle aircraft down from FL100 to 1.500 ft AGL in a radar vectoring environment results in a fuel burn gain of approximately 50 kg against a reference which is already influenced by a number of non-declared but CDOcompatible approaches. Detailed analysis of the descent profiles has clearly revealed that there is a potential for further savings through improved flying techniques.
Airbus A330-300. Although not fully equal, the overall findings for the Airbus A330-300 flights largely concur with those for the Airbus A319. Ten flights proceed along an eastbound pattern; the remainder (13) follow a westbound pattern into the landing runway(s). Note that no single descent path is above the reference profile below FL100; five are more or less on the reference profile. The remainder of the flights are below the reference profile, but somewhat less than the average A319 descent profiles. Although not known to which extent (the FDM-data do not record the details), 9 flights make use of the speed brake below FL100. For all the analysed descents we recorded/calculated following fuel burn (kg): FL60-1500 FL80-1500 FL100-1500 Minimum value
79.7
99.7
131.3
Maximum value
345.2
380.9
528.5
Median value
141.1
191.3
224.6
Average value
170.1
208.8
245.6
Standard deviation
68.2
76.2
92.8
Table 5-4 - Airbus A333 – Overview of all flights - Fuel Burn.
– Phase 2 Version 4.2 - 15/02/2012 - Page 126
B3 SESAR JU PROJECT
For 5 out of the 12 flights with an explicit CDO-approval delivered, the EFICAT-tool does not consider the flown descent below FL100 to be compatible with a “CDO”. This finding is to a large extent confirmed by the FDM-data analysis. For all descents with a CDO-approval, we have following fuel burn (kg):
Altitude
Track miles
FL60-1500
FL80-1500
FL100-1500
Minimum value
89.0
35.0
79.7
99.7
131.3
Maximum value
149.0
58.0
239.6
270.5
287.7
Median value
110.5
41.0
133.0
152.0
197.2
Average value
111.3
43.5
137.2
165.3
196.0
Standard deviation
18.1
6.6
41.1
46.0
44.2
Table 5-5 - Airbus A333 – Overview of all flights without CDO-approval - Fuel Burn. For 8 out of the 17 flights which did not receive an explicit CDO-approval, the EFICAT tool nevertheless considers the flown profile below FL100 to be compatible with a CDO-profile. For all descents without a CDO-approval, we have following fuel burn (kg):
FL60-1500 FL80-1500 FL100-1500 Minimum value
84.4
112.5
141.3
Maximum value
345.2
380.9
528.5
Median value
223.7
271.0
296.0
Average value
205.9
256.2
299.7
Standard deviation
75.3
75.6
103.2
Table 5-6 - Airbus A333 – Overview of all flights without CDO-approval – Fuel Burn. Comparison of the CDO “Marked” against “Not_Marked” flights leads to following results (kg): FL60-1500 FL80-1500 FL100-1500 Median value
-90.7
-119.0
-98.8
Average value
-68.7
-90.9
-103.6
– Phase 2 Version 4.2 - 15/02/2012 - Page 127
B3 SESAR JU PROJECT Conclusions: The conduct of a CDO-approach with an Airbus A330-300 widebody aircraft down from FL100 to 1.500 ft AGL in a radar vectoring environment results in a fuel burn gain of approximately 100 kg against a reference which is already influenced by a number of nondeclared but CDO-compatible approaches. Detailed analysis of the descent profiles here as well has revealed that there is a potential for further fuel burn savings.
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B3 SESAR JU PROJECT
Table 5-7 - Overview Ov of all analyzed flights - Airbus A319. A319
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Table 5-8 - Overview of all analyzed flights with CDO-approval - Airbus A319.
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Table 5-9 - Overview of all analyzed flights without CDO-approval approval - Airbus A319.
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Table 5-10 - Overview of all analyzed flights - Airbus A333. A333
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Table 5-11 - Overview of all analyzed flights with CDO-approval - Airbus A333. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 133
B3 SESAR JU PROJECT
Table 5-12 - Overview of all analyzed flights without CDO-approval approval - Airbus A319. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 134
B3 SESAR JU PROJECT 5.6
CALCULATED NOISE IMPACT IMPACT
As previously explained in section4.3.5, the possible noise impact arising from CDO facilitation is simulated (or calculated) rather than monitored. The effects on noise were studied by analyzing the flights from which FDM-data were made available by Brussels Airlines (A333 and A319)..Firstly the applied method is described in detail for one test flight.In the next two paragraphs the calculated noise impact of the different flights is compared in two different ways: •
Based on the area withinthe noise contour(s)
•
Based on the LAmax-profiles, as well as straight under the flight track as at a distance of 0.5 NM excentrical from the flight track
The last paragraph of this chapter deals with whether or not the CDO facilitation does have an effect on the position of the ground track of the flight. 5.6.1
NOISE IMPACT IMPACT CALCULATION – TYPICAL EXAMPLE
In this paragraph the working method to calculate the noise impact on the ground based on the FDM data of the flight (see section 4.3.5) is illustrated for the Airbus 330-300 flight with reference A333_22.This method is applied in the same way for all the other analyzed flights. By analogy with the fuel burn gain and carbon emission calculations, for the calculation of the noise impact on the ground only the last part of the flight from FL100 to touchdown is considered.For flight levels above FL100 it can be assumed that the noise levels on the ground will be more limited due to the geometrical expansion of the sound field and the sound absorption in the air. As explained in section 4.3.5the INM calculation model requires three parameters in function of the distance to landing to calculate the noise impact on the ground.Two of these parameters can be immediately derived from the provided FDM – data: the altitude of the aircraft and the true air speed.The distance to touchdown is calculated by integration of the groundspeed over time.The result for the altitude (left axis) and the speed (right axis) for the A333-flight of the example is shown in the figure below.It can be seen from this graph that in this example the aircraft was below the 3° referenc e profile.In the level flight segment at an altitude 2.000 ft, just before the ILS-interception, the speed shows an (almost) constant value.
– Phase 2 Version 4.2 - 15/02/2012 - Page 135
B3 SESAR JU PROJECT 16000
350 Altitude
14000
300
TAS
12000
Altitude [ft]
10000 200 8000 150 6000 100
4000
True Air Speed [kt]
250
50
2000 0
0 0
10
20 Distance to landing [NM]
30
40
Figure 5-73 - Airbus A330-300 arrival ref. A333_22: altitude and true air speed (TAS). Thethird parameter required to calculate the noise impact with INM is the the corrected net thrust (CNT) per engine. As stated in section 4.3.5 there exists no straight forward method to derive the (CNT) per engine from the engine rotation speed available in the FDM database.Instead CNT can be determined by solving the equation of motion of the aircraft. The resulting CNT for this example is given in the graph below (blue line, left axis).Also on this graph the use of the speed brakes (red line) and the throttle percentages of the engines (brown line, right axis) are showed. On the graph can be seen that the calculated value of the CNT results innegative values at the moment speed brakes are used. This is a logical result because the drag over lift coefficient which is used to solve the equation of motion is based only on the flap settings of the aircraft.No coefficients are available within INM for configurations of the aircraft with speed brakes on.This results in a drag-over-lift value which is much lower compared to reality and consequently a negative value of CNT.However, when speed brakes are on, it can correctly be assumed that the engines are in idle mode.In this way, idle thrust was assumed as input for INM at the moment speed brakes were switched on (see green line on the graph). â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 136
B3 SESAR JU PROJECT In the zone with a distance between 8 and 27 nautical miles to landing, smaller negative values for CNT are calculated.The explanation for these negative values is that also here the engines are in idle thrust mode.At that moment the engines are not propulsive and instead provide some additional drag resulting from the air going true the fan.Also this drag is not taken into account when solving the equation of motion resulting in the negative calculated value for CNT.Consequently idle thrust can be assumed in this zone for the INM CNT profile (green line on graph). In the zone with a distance between 0 and 8 nautical miles to landing positive values for CNT are found meaning the engines are used to provide power.Especially in the level flight zone a lot of power is required to remain a constant speed.Also when intercepting the ILS and in the final part of the landing additional power was required. However CNT cannot be calculated straight forward from the rotational speed of the engines (throttle), the profile of the throttle confirms the shape of the calculated CNT values.Until a distance of 8 nautical miles to the airport the value of the rotational speed of the engines decreases slowly from 34% until 26%, corresponding to idle mode.In the zone with a distance between 0 and 8 nautical miles to landing the shape of the profile of the calculated value of CNT corresponds very well to the shape of the throttle value.
20000
300 Corrected Net thrust per engine Corrected net thrust per engine - INM input
250
Throttle N1 speed brakes
10000 200 5000 150 0 0
10
20
30
40
Throttle N1 [%]
Corrected net thrust per engine [lbs]
15000
100 -5000 50
-10000
-15000
0 Distance to landing [NM]
Figure 5-74 - Airbus A330-300 arrival ref. A333_22: calculated CNT per engine.
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B3 SESAR JU PROJECT The figure below shows the results of the calculated LAmax noise contours of 60 (red), 65 (orange), 70 (blue) and 75 (green) dB(A) with INM 7.0b for this example.For all the simulation it is assumed that the aircraft arrives on a ground track in line with the runway.However this doesnâ&#x20AC;&#x2122;t correspond to reality, the influence on the calculated noise contour will be minor (execpt for the geographical position of the noise contour). In this way the noise contours of the different flights can easily be compared.The runway is (in each case) located on the left side of the figure.
Figure 5-75 - Airbus A330-300 arrival ref. A333_22: LAmax noise contours of 60 (red line), 65 (orange line), 70 (blue line) and 75 (green line) dB(A). It can be seen from the noise contours that the further away from the airport the more the LAmax-levelgenerally decreases due to the increasing distance between source and receiver (higher altitude of the aircraft).When the engines are in idle mode, the most part of the noise is generated by the aircraft passing true the air (ramp noise).However at locations where the engines are used to provide thrust it can be seen that noise contours become wider. The more power is applied, the more noise is generated by the engines and the wider the resulting noise contours become (surface within the contours increases). It should be observed that, as explained in section 4.3.5, the noise at the receiver positions is calculated in INM 7.0b based on noise-power-distance curves.For each type of aircraft there is only one set of these curves available.This means that whether speed brakes are switched on or not the same curves are applied resulting in the same noise level.However in reality the use of speed brakes can generate a significant amount of ramp noise due to the extra drag that is generated.Consequently, the calculated noise in the zones where speed brakes are applied is an underestimation of the reality. Besides the speed brake problem, it can be concluded that with the followed method a realistic simulation of the noise impact of the analyzed flights could be realised taking to account real FDM data of the aircraft.
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B3 SESAR JU PROJECT 5.6.2
AREA OF THE LAMAX NOISE CONTOURS
For the 23 A330-300 and 33 A319 analyzed flightswith FDM-data provided the LAmax-noise contours are calculated with the method described above.The area of noise contours is determined within a GIS environment.In this paragraph a comparison is made between the total area within these noise contours for the different flights.The smaller the surface within the noise contours, the less the noise impact on the ground. 5.6.2.1
AIRBUS 330-330 ANALYZED FLIGHTS
For the A330-300 flights the lowest calculated LAmax noise contour is the noise contour of 60 dB(A).In the figure below the area of this noise contour is compared for the different flights.The marked flights (CDO approved flights) are presented on the left side of the figure while the non marked flights (no explicit CDO approval) are presented on the right side.In addiotion a distinction is made between estimated CDO-profiles below FL100 (green squares) and the ‘No CDO’ - profiles (red squares) according toEFICAT analysis.
– Phase 2 Version 4.2 - 15/02/2012 - Page 139
B3 SESAR JU PROJECT Area within LAmax noise contour of 60 dB(A) A330-300 test flights 10000 Efficat CDO < FL100 9000
Efficat NO CDO < FL100
(A333_01)
8000 (A333_08)
7000
Area [Ha]
6000
(A333_22)
5000 4000 (A333_06)
3000 2000 1000 0
Marked flights
Non marked fligths
Figure 5-76- Area of the LAmax noise contour of 60 dB(A) for the Airbus A330-300 analyzed flights. If the marked flights are compared to the non marked flights it is clear that the average area for the marked flights (4.893 ha) is significantly lower than the area for the non-marked flights (6.564 ha), resulting in an average reduction of about 25%.If only the marked flights that flew a CDO under FL100 are taken into account the average area decreases until 4.400 ha. In the group of the marked flights there is a clear distinction between the CDO -and the non CDO profiles (as estimated by EFICAT analysis) where the area of the noise contour is significantly smaller for the CDO flights. This distinction is less clear in the group of the non marked flights, as previously concluded: a part of the flights, not receiving an explicit CDOapproval, shows a flown profile below FL100 to be compatible with a CDO-profile (EFICAT) On the graph above four different analyzed flights are indicated with their reference number. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 140
B3 SESAR JU PROJECT In the following section these four flights are analysed in detail based on their speed, altitude and CNT profiles. The LAmax noise contours of these four flights are compared in the figure below.
Figure 5-77 - Airbus A330-300 analyzed flights: LAmaxnoise contours of 60, 65, 70 and 75 dB(A).
â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 141
B3 SESAR JU PROJECT Ref A333_01 (NON MARKED, NO CDO (EFICAT)) 16000
300
14000
Throttle N1
250
speed brakes
12000
200
10000 8000
150
6000
100
Throttle N1 [%]
Corrected net thrust per engine [lbs]
Corrected net thrust per engine - INM input
4000 50
2000 0
0 0
10
20 30 Distance to landing [NM]
40
50
16000
350 Altitude
14000
300
TAS
250
10000 200 8000 150 6000 100
4000
True Air Speed [kt]
Altitude [ft]
12000
50
2000 0
0 0
10
20 30 Distance to landing [NM]
40
50
Figure 5-78 - A333_01 (NON MARKED, NO CDO (EFICAT)). The area of the LAmaxnoise contour of 60 dB(A) of this flight is 8.840 ha, which is the largest value of all the A330-300 analyzed flights.The main reason is that the flight profile is for the shown section contantly below the reference profile. At a distance of about 20 NM from touchdown the flight already levels off at 3.000 ft altitude to intercept the ILS at about 9.5 NM from touchdown.In some parts during this extended level off phase a considerable amount of engine thrust shows to be required to maintain the speed at a constant level. This results in an significant increase of the noise contours.
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B3 SESAR JU PROJECT Ref A333_06 (NON MARKED, CDO (EFICAT)) 14000
300
12000
Throttle N1
250
speed brakes
10000 200 8000 150 6000 100 4000
Throttle N1 [%]
Corrected net thrust per engine [lbs]
Corrected net thrust per engine - INM input
50
2000 0
0 0
5
10
15 20 25 Distance to landing [NM]
30
35
40
16000
350 Altitude
14000
300
TAS
250
10000 200 8000 150 6000 100
4000
True Air Speed [kt]
Altitude [ft]
12000
50
2000 0
0 0
5
10
15 20 25 Distance to landing [NM]
30
35
40
Figure 5-79 - A333_06 (NON MARKED, CDO (EFICAT)). The area of the LAmaxnoise contour of 60 dB(A) of this flight is 3.623 ha, the smallest of all A330-300 analyzed flights.However this flight follows a very successful CDO-profile (close to the reference profile of 3°) it was not marked. Mor eover, during the descent from FL100 until the interception of the ILS the engines were almost always in idle mode. The only drawback of this flight is the use of the speed brakes in the zone with distance from 14 NM until 8 NM to landing.As remarked before, it was not possible to take this into account in the noise contour calculation with INM 7.0b.
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B3 SESAR JU PROJECT Ref A333_08 (NON MARKED, CDO (EFICAT)) 300 Corrected net thrust per engine - INM input
18000
Throttle N1
16000
250
speed brakes
14000
200
12000 10000
150
8000 100
6000 4000
Throttle N1 [%]
Corrected net thrust per engine [lbs]
20000
50
2000 0
0 0
10
20 30 Distance to landing [NM]
40
50
16000
350 Altitude
14000
300
TAS
250
10000 200 8000 150 6000 100
4000
True Air Speed [kt]
Altitude [ft]
12000
50
2000 0
0 0
10
20 30 Distance to landing [NM]
40
50
Figure 5-80 - A333_08 (NON MARKED, CDO (EFICAT)). The area within the LAmaxnoise contour of 60 dB(A) of this flight is 7.272 ha.However this flight is considered a CDO below FL100 based on the EFICAT analysis the resulting noise contour is rather large.The reason here is that also this flight is below the reference profile.Especially in the zone from 33 to 25 NM distance to landing the flight makes a steep descent from approximately FL80 to FL40.Speed brakes are not used in this zone resulting in an increase of the speed during this descent.After the sharp descent the aircraft slowly descends further continuously until the interception of the ILS at 2.000 ft.Also speed is reduced slowly during this flights phase.Except for the zone around 14 NM distance to landing,engines were in idle mode resulting in a positive noise impact. Speed brakes were not used descending from FL100 until touchdown. â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 144
B3 SESAR JU PROJECT Ref A333_22 (MARKED, NON CDO (EFICAT)) 16000
300
14000
Throttle N1
250
speed brakes
12000
200
10000 8000
150
6000
100
Throttle N1 [%]
Corrected net thrust per engine [lbs]
Corrected net thrust per engine - INM input
4000 50
2000 0
0 0
5
10
15 20 25 Distance to landing [NM]
30
35
40
16000
350 Altitude
14000
300
TAS
250
10000 200 8000 150 6000 100
4000
True Air Speed [kt]
Altitude [ft]
12000
50
2000 0
0 0
5
10
15 20 25 Distance to landing [NM]
30
35
40
Figure 5-81 - A333_22 (MARKED, NON CDO (EFICAT)). The area of the LAmaxnoise contour of 60 dB(A) of this flight is 6.-207 ha, the highest value for the CDO approved flight test with A330-300. Also for this flights the main reason is that the flight is below reference profile.Even more there is a level off segment of about 3 NM to touchdown at 2.000 ft before the interception.Because also the speed is constant in this part of the flight a lot of engine thrust was necessary generating an extra noise impact on the ground (at this low height).
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B3 SESAR JU PROJECT 5.6.2.2
AIRBUS 319 ANALYZED FLIGHTS
The A319 is a smaller aircraft compared to the A333 aircraft resulting in smaller noise contours.For most approaches the LAmax-noise contour of 60 dB(A) is limited to the zone where the flight is on the ILS.As the B3 CDO concept aims at improving (CO2, fuel, noise) the stage before aircrafts intercept the ILS, it was decided to use the area of the LAmax noise contour of 50 dB(A) to compare the different A319 test flight (see graph below).
Area within LAmax noise contour of 50 dB(A) A319 test flights 12000 Efficat CDO < FL100 (A319_16)
Efficat NO CDO < FL100 10000
8000
Area [Ha]
(A319_19)
6000
4000
(A319_26)
(A319_15)
2000
0
Marked flights
Non marked fligths
Figure 5-82 - Area of the LAmax noise contour of 50 dB(A) for the Airbus A319 analyzed flights. Concerning the surface of the LAmax noise contour for the A319 analyzed flights similar results are found as for the A330-300 flights: â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 146
B3 SESAR JU PROJECT • The average surface of the CDO approved flights (5.517 ha) is lower as for the non CDO approved flights (6.620 ha) meaning a decrease of about 17%. • In the group of the CDO approved flights it is clear that those flight that were considered CDO (under FL100 by EFICAT), have the smallest noise contour area.The averages area of the LAmax noise contour of 50 dB(A) for these flights is 4.780 ha, 28% lower than for the non CDO approved flights. • This distinction between EFICAT-CDO flights and EFICAT-non CDO flights is less clear for the non CDO marked flights, however the flights with the lowest noise contour area are also mostly CDO flights. On the graph above four different analyzed flights are indicated with their reference number. In the following section these four flights are analysed in detail based on their speed, altitude and CNT profiles. The LAmax noise contours of these four flights are compared in the figure below.
Figure 5-83 - Airbus A319 analyzed flights: LAmaxnoise contours of 50, 55, 60 and 65 dB(A).
– Phase 2 Version 4.2 - 15/02/2012 - Page 147
B3 SESAR JU PROJECT Ref A319_15 (MARKED, CDO (EFICAT)) 8000
300
7000
Throttle N1
250
speed brakes
6000
200
5000 4000
150
3000
100
Throttle N1 [%]
Corrected net thrust per engine [lbs]
Corrected net thrust per engine - INM input
2000 50
1000 0
0 0
5
10 15 20 Distance to landing [NM]
25
30
35
16000
350 Altitude
14000
300
TAS
250
10000 200 8000 150 6000 100
4000
True Air Speed [kt]
Altitude [ft]
12000
50
2000 0
0 0
5
10 15 20 Distance to landing [NM]
25
30
35
Figure 5-84 - A319_15 (MARKED, CDO (EFICAT)). The area of the LAmaxnoise contour of 50 dB(A) of this flight measures 3.638 ha, the smallest of all A319 analyzed flights. The flight was CDO approved by the ATC. This flight is an example of a well executed CDO.The altitude profile corresponds very close to a 3° reference profile and during most time of t he descent the engines were in idle mode.However the use of the speed brakes could not be avoided in zone with a distance from 12 to 6 NM to landing to avoid the aircraft accelerating during the descent.
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B3 SESAR JU PROJECT Ref A319_16 (NON MARKED, NON CDO (EFICAT)) 6000
300 Throttle N1
5000
250
speed brakes
4000
200
3000
150
2000
100
1000
50
0
Throttle N1 [%]
Corrected net thrust per engine [lbs]
Corrected net thrust per engine - INM input
0 0
10
20 30 Distance to landing [NM]
40
50
60
16000
350 Altitude
14000
300
TAS
250
10000 200 8000 150 6000 100
4000
True Air Speed [kt]
Altitude [ft]
12000
50
2000 0
0 0
10
20 30 Distance to landing [NM]
40
50
60
Figure 5-85 - A319_16 (NON MARKED, NON CDO (EFICAT)). The area of the LAmaxnoise contour of 50 dB(A) of this non CDO approved flight is 11.022 ha which is the highest value of all A319 analyzed flights. This effect is caused by an altitude profile that is far below the reference profile.Moreover the speed is contained at constant level during this approach from 40 NM to 8 NM from touchdown which leads up to a considerably constant high engine power (and noise!) required to execute the flight.
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B3 SESAR JU PROJECT Ref A319_19 (MARKED, NON CDO (EFICAT) 6000
300 Throttle N1
5000
250
speed brakes
4000
200
3000
150
2000
100
1000
50
0
Throttle N1 [%]
Corrected net thrust per engine [lbs]
Corrected net thrust per engine - INM input
0 0
5
10 15 20 Distance to landing [NM]
25
30
35
16000
400 Altitude
350
TAS
12000
300
10000
250
8000
200
6000
150
4000
100
2000
50
0
True Air Speed [kt]
Altitude [ft]
14000
0 0
5
10 15 20 Distance to landing [NM]
25
30
35
Figure 5-86 - A319_19 (MARKED, NON CDO (EFICAT). The area of the LAmaxnoise contour of 50 dB(A) of this CDO approved flight is 7.665 ha, more than double of the flights with the smallest noise contour area. However the flight is close to the 3° line at FL100 , it descends steep resulting in a level off at 2.000 ft over a distance of about 10 NM.Given the high speed below FL100, as previously reported, the aircraft had to loose speed during the level-off step so that except for a small part the engines were in idle thrust mode.
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B3 SESAR JU PROJECT Ref A319_26 (NOT MARKED, CDO (EFICAT)) 7000
300
6000
Throttle N1
250
speed brakes
5000 200 4000 150 3000 100 2000
Throttle N1 [%]
Corrected net thrust per engine [lbs]
Corrected net thrust per engine - INM input
50
1000
0
0 0
10
20 30 Distance to landing [NM]
40
50
350
16000 Altitude
14000
300
TAS
250
10000 200 8000 150 6000 100
4000
True Air Speed [kt]
Altitude [ft]
12000
50
2000 0
0 0
10
20 30 Distance to landing [NM]
40
50
Figure 5-87 - A319_26 (NOT MARKED, CDO (EFICAT)). The area of the LAmaxnoise contour of 50 dB(A) of this non CDO approved flight is 3.826 ha. As can be seen on the altitude profile this flight is at FL100 about 3.000 ft above the reference line of 3°.As discussed before this leads to a higher fuel consumption (and carbon emissions). This position of the aircraft requires a very steep descent to intercept the ILS at 2.000 ft.As can be seen on the graph even the use of the speed brakes can’t avoid the accelaterion of the aircraft during this descent.However we were not able to take the effect of the speed – Phase 2 Version 4.2 - 15/02/2012 - Page 151
B3 SESAR JU PROJECT brakes into account for the noise impact calculation, it can be assumed that the gain in noise level due to the higher position of the aircraft will be counteracted by the use of the speed brakes. This flight had also a constant speed after the ILS interception.This required a lot of engine thrust resulting in a very noisy last part of the landing (after ILS interception).In this zone the noise contours are wider as for most other flights studied. 5.6.3 5.6.3.1
LAMAX-NOISE PROFILES AIRBUS 330-330 ANALYZED FLIGHTS
The figure below shows the LAmax noise profile for the different A330-300 analyzed flights in function of the distance to landing straight under the flight path.The green lines present the profiles of the flights that were CDO approved by ATC (marked) while the brown lines present the profiles for the non CDO approved flights (non marked). As a reference the red line presents the LAmax profile of a flight that follows perfectly a 3° slope descent to the airport and has the engines in IDLE mode.This line is only presented in zone starting from 10 NM to landing. Closer to the airport the interception of the ILS influences the thrust profile. As can be seen on the graph the LAmax value generally decreases in function of the distance to landing due to the increasing distance between source and observer.However in zones where engines power is applied this decrease is interrupted and higher noise levels occur.
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B3 SESAR JU PROJECT LAmax noise profile for A333 under the flight track 80
Marked flights (CDO approved) Non marked flights (NO CDO approval)
75
3° - IDLE thrust reference
70 LAmax [dB(A)]
65 60 55 50 45 40 35 30 5
10
15 Distance to landing [NM]
20
25
Figure 5-88 - Airbus A330-300 analyzed flights: LAmaxnoise profile under the flight track. To compare the different flights the average difference between the LAmax profile of the flight and the 3° - idle thrust reference profile is deter mined for each flight in the zone with a distance between 10 and 25 NM to landing.As explained before this is the zone where noise benefits of CDO approaches can be expected.The result of this analysis is presented in the figure below.This graph is created in the same way as for the comparison of the area of the noise contours in the previous paragraph: a distinction is made between marked and non marked flights and the color indicates whether the flight is analysed as a CDO below FL100 by EFICAT or not.The references of the flights discussed in detail in the previous section are also indicated on the graph.
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B3 SESAR JU PROJECT Average LAmax noise difference in the zone 10 - 25 NM to landing compared to 3° - idle thrust profile Under flight track A330-300 test flights 10 Efficat CDO < FL100 9 Efficat NO CDO < FL100
(A333_01)
LAmax difference [dB(A)]
8 7
(A333_08)
6 5 (A333_22)
4 3 2 1 (A333_06)
0
Marked flights
Non marked fligths
Figure 5-89 - Airbus A330-300 analyzed flights: average LAmaxnoise difference in the zone 10 – 25 NM to landing compared to 3° - idle th rust profile straight under the flight track. The average LAmax noise difference is clearly smaller for the marked flights (3.1 dB(A)) compared to the non marked flights (5.8 dB(A)).If only the marked flights which are considered CDO below FL100 (EFICAT) are taken into account the average difference is 2.3 dB(A). The same analysis is made for a position of the receiver on the ground at 0.5 NM excentrical from the flight track.The resulting LAmax-profiles and the average difference compared to a 3° idle thrust profile (in the zone 10-25 NM to lan ding) are presented in the figures below. Generally the same conclusions are valid for this excentrical position of the receiver (compared to the position under the flight track) however the noise differences between the – Phase 2 Version 4.2 - 15/02/2012 - Page 154
B3 SESAR JU PROJECT different flights are smaller.This is caused by the fact that the lateral attenuation of the aircraft noise is higher for smaller values of the viewing angle of the aircraft from the observer (i.e. when the aircraft is lower).This effect partially counteracts the noise benefit of a higher position of the aircraft.
LAmax noise profile for A333 under 0.5 NM excentrical from the flight track 80
Marked flights (CDO approved) Non marked flights (NO CDO approval)
75
3° - IDLE thrust reference
LAmax [dB(A)]
70 65 60 55 50 45 40 35 30 5
10
15 Distance to landing [NM]
20
25
Figure 5-90 - Airbus A330-300 analyzed flights: LAmaxnoise profile 0.5 NM excentrical from the flight track.
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B3 SESAR JU PROJECT Average LAmax noise difference in the zone 10 - 25 NM to landing compared to 3° - idle thrust profile 0.5 NM excentrical from flight track A330-300 test flights 10 Efficat CDO < FL100 9 Efficat NO CDO < FL100
LAmax difference [dB(A)]
8 7 (A333_01)
6 5
(A333_08)
4 3
(A333_22)
2 1 (A333_06)
0
Marked flights
Non marked fligths
Figure 5-91 - Airbus A330-300 analyzed flights: average LAmaxnoise difference in the zone 10 – 25 NM to landing compared to 3° - idle th rust profile at 0.5 NM excentrical from the flight track.
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B3 SESAR JU PROJECT 5.6.3.2
AIRBUS 319 ANALYZED FLIGHTS
The figure below shows the LAmax noise profile for the different A319 analyzed flights in function of the distance to landing straight under the flight path.The green lines present the profiles of the flights that were CDO approved by ATC while the brown lines present the profile for the non CDO approved flights. As a reference the red line presents the LAmax profile of a flight that follows perfectly a 3° slope descent to the airport and has the engines in IDLE mode.This line is only presented in zone starting from 10 NM to landing.Closer to the airport the interception of the ILS influences the thrust profile. If the profiles of the A319 are compared to the profiles of the Airbus 330-300 a shift of about 10 dB(A) towards lower values can be noticed.However the spread of the values for the different flights is of the same magnitude.
LAmax noise profile for A319 under the flight track 80 Non Marked flights (NO CDO approval) Marked flights (CDO approval) 3° - IDLE thrust reference
75 70 65
LAmax [dB(A)]
60 55 50 45 40 35 30 25 20 5
10
15
20
25
Distance to landing [NM]
Figure 5-92 - Airbus A319 analyzed flights: LAmaxnoise profile under the flight track.
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B3 SESAR JU PROJECT To compare the different flights the average difference between the LAmax profile of the flight and the 3° - idle thrust reference profile is deter mined for each flight in the zone with a distance between 10 and 25 NM to landing.The result of this analysis is presented in the figure below.This graph is created in the same way as for the comparison of the area of the noise contours in the previous paragraph: a distinction is made between marked and non marked flights and the color indicates whether the flight is analysed as a CDO below FL100 by EFICAT or not.The references of the flights discussed in detail in the previous section are also indicated on the graph.
Average LAmax noise difference in the zone 10 - 25 NM to landing compared to 3° - idle thrust profile under the flight track A319 test flights 10 Efficat CDO < FL100 (A319_16)
Efficat NO CDO < FL100 8
LAmax difference [dB(A)]
(A319_18)
6
4
2
0 (A319_15)
-2 (*) (A319_26)
-4
Marked flights
Non marked fligths
Figure 5-93 - Airbus A319 analyzed flights: average LAmax noise difference in the zone 10 – 25 NM to landing compared to 3° - idle thrust profile straight under the flight track.
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B3 SESAR JU PROJECT (*) Remark A319_26 : for this flight an average LAmax difference is found of about -3 dB(A).As discussed in the previous section this flight was high above its reference profile. However speed brakes had to be applied to realise a steep descent to intercept the ILS.As explained, this effect could not be modeled by the INM but will result in higher noise levels.Also in the zone after the ILS interception this flight was very noisy due to the necessary engine thrust to maintain a constant speed.Because of this reason the the total area of the LAmax noise contour of 50 dB(A) was not the smallest of all flights studied. The average LAmaxnoise difference is smaller for the marked flights (2.7 dB(A)) compared to the non marked flights (4.2 dB(A)). Also here there is a clear distinction in the group of the marked flights between the flights that are considered a CDO below FL100 (EFICAT) and the flights that are not.The CDO have an average difference of 1.4 dB(A) while the non CDO flights have an average difference of 5.1 dB(A). The same analysis is made for a position of the receiver on the ground at 0.5 NM excentrical from the flight track.The resulting LAmax-profiles and the average difference compared to a 3° idle thrust profile (in the zone 10-25 NM to landing) are presented in the figures below. Generally the same conclusions are valid for this excentrical position of the receiver however the noise differences between the different flights are smaller.This is caused by the fact that the lateral attenuation of the aircraft noise is higher for smaller values of the viewing angle of the aircraft from the observer (i.e. when the aircraft is lower).This effect counteracts partially the noise benefit of a higher position of the aircraft.
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B3 SESAR JU PROJECT LAmax noise profile for A319 0.5 NM excentrical from flight track 70 Non Marked flights (NO CDO approval) Marked flights (CDO approval) 3° - IDLE thrust reference
65
LAmax [dB(A)]
60 55 50 45 40 35 30 5
10
15
20
25
Distance to landing [NM]
Figure 5-94 - Airbus A319 analyzed flights: LAmaxnoise profile 0.5 NM excentrical from the flight track.
– Phase 2 Version 4.2 - 15/02/2012 - Page 160
B3 SESAR JU PROJECT Average LAmax noise difference in the zone 10 - 25 NM to landing compared to 3° - idle thrust profile 0.5 NM excentrical from flight track A319 test flights 10 Efficat CDO < FL100
LAmax difference [dB(A)]
8
Efficat NO CDO < FL100 (A319_16)
6
4
(A319_19)
2
0 (A319_15)
-2 (A319_26)
-4
Marked flights
Non marked fligths
Figure 5-95 - Airbus A319 analyzed flights: average LAmaxnoise difference in the zone 10 – 25 NM to landing compared to 3° - idle thrust profile at 0.5 NM excentrical from the flight track. 5.6.4
IMPACT ON LATERAL ROUTES ROUTES
To study the possible difference between the ground track of CDO approved flights and CDO non approved flights the ground tracks of the flights arrived at Brussels Airport in the months April and May 2011 on runways 25L and 25R were analysed.To avoid as much as possible the impact of other parameters influencing the position of the ground tracks only the flights during the most calm period of the day were selected (from midnight until 0.5 am).Radar data available in the NMS of Brussels Airport was used and linked to the Belgocontrol list of CDO approvals for these months.
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B3 SESAR JU PROJECT In the figures below the red lines show the ground track of the CDO approved fligts while the green lines show the ground tracks of the flights without CDO approval.The upper graph is for the arrivals on runway 25R while the lower shows the arriavsl in runway 25L. The main conclusion that can be drawn from this graph is that no new zones are overflown by the CDO approved flights approaching Brussels Airport that were not overflown by the non CDO approved flights. If other small visually noticeable shifts (e.g. the average route of the landings on runway 25R coming from the east is lying a bit more to the south) are representivecan not be concluded from these graphs.
Figure 5-96 - Visualization of ground tracks on runway 25R.
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B3 SESAR JU PROJECT
Figure 5-97 - Visualization of ground tracks on runway 25L.
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B3 SESAR JU PROJECT
5.6.5
CONCLUSION NOISE ANALYSIS ANALYSIS
Next to reducing fuel burn and emissions, an objective of the B3-project was to study the potential aircraft noise reductionbenefits associated with continuous descent approaches in the vicinity of Brussels Airport. In order to study these benefits associated with CDO facilitation noise modeling was preferred rather than noise monitoring because of the relatively low individual aircraft noise levels in the areas where CDO is deployed (i.e. typically at more than 10 nm from the threshold) and given the potential for significant variations in factors that can influence measurements Operational flight data (FDM) provided by Brussels Airlines were used to simulate more dan 50 approaches in detail. The analysis of the noise simulations shows significant gains can be realised on the noise impact on the ground in the area between FL100 and interception of ILS. Below this area, which occurs typically at 2,000ft or 3,000ft, no differences with a conventional arrival are significant. At altitudes more 10,000ft CDO noise benefits are negligible. Intermediate level-off segments, other than for stabilization reasons, during descent have to be avoided. During these phases a higher noise impact can be expected not only due to a smaller source – receiver distance but also because in most cases additional engine thrust is required. Unnecessary speed brake activation should be avoided during descent phase because of the extra noise generation due to a higher drag value of the aircraft passing true the air. Finally, it should be kept in mind that the largest noise impact occurs in the zone closer to the airport, below the altitude at which the ILS is intercepted. In this zone no effects assigned to a CDO-approach can be expected in comparison to a coventional “step down” approach.
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B3 SESAR JU PROJECT 6.
COMMUNICATION PLAN
Several communication actions have been organised during phase 2 of the B3-project.These actions focus on internal communication as well as external communications. After the delivery of the final report, we will continue to communicate on the project. A communication action plan has been developed (see infra).
6.1
IMPLEMENTED COMMUNICATION COMMUNICATION ACTIONS DURING PHASE 2
6.1.1
BELGOCONTROL
Hereunder you will find a list of communication actions which Belgocontrol realised in 2011. Media Hubnews
Monthly emailing to ATCOs Face to face ATC Global Amsterdam
Type of Media - Personnel Magazine
Target Group Whole staff
Date No. 14 – 03/ 2011 (page 5)
Subject B: phase 1 Congratulations of SESAR JU
No. 15 – 07/2011 (page 4)
Brussels Airport Environment Award Overview of marked CDOs
- Email with attachment
APP ATCOs
Monthly 2011
- Refresher courses - Participation to FABEC booth with information on B3 - Distribution of flyer on FABEC projects participating in AIRE
APP ATCO’s
02/2011
Internal : FABEC partners. External : all stakeholders
March 2011
– Phase 2 Version 4.2 - 15/02/2012 - Page 165
Briefing on B3 project Summary of the project
B3 SESAR JU PROJECT FABEC Newsletter Overlegforum
- Digital - Presentation
Local residents representatives
30/09/2011
FABEC Standing Committee Environment
- Presentation
Members of the FABEC Standing Committee Environment
07/10/2011
Eurocontrol CDA workshop
- Presentation
ANSPs, Airlines, Airport operators
11&12/10/2011 Experience with the Eurocontrol EFICAT tool
Belgocontrol portal and website
- Continuous update of information on project â&#x20AC;&#x201C; dedicated pages on CDO (and B3) on portal and website -
Internal and external stakeholders
Continuously in 2011
-
From page 30 to 34, published June 2011
-
Belgocontrol Annual Report 2010
No 11
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Article on B3 project Presentation of the CDOproject How the measurement of CDO is addressed in the B3-project
Dedicated chapter on sustainable performance with extensive information on the B3 project and CDOs.
B3 SESAR JU PROJECT 6.1.2
BRUSSELS AIRPORT
The Brussels Airport Company published several articles in its internal media and organised face-to-face communication. The Brussels Airport Company published several articles in its internal and external media and organised (existing) meetings with the surrounding communities Media Type of Media Brussels Airport Intranet Bulletin Intranet
Target Group Whole staff
Brussels Airport Newsletter News Consultative Project Bodies Presentation
Airport Community Airport Surrounding Communities
6.1.3
Date October 2010
Subject Presentation of the project and of the partners involved No. 41 – Short article on the October 2010 B3Sesar project September Presentation of the 2010 project – Q&A
BRUSSELS AIRLINES
Just like Belgocontrol and The Brussels Airport, Brussels Airlines focus was during phase 1 on creating staff awareness. This target was reached via several internal communication actions. B3 was included as from the start of phase one in the company wide 'b.green' project that covers and steers all environmental actions of the airline. Internal Communication messages reached all internal stakeholders via various channels: -
Presentation to the Executive Management Presentation of B3 in internal newsletters, TV info screens and communication messages Intranet 'b.green' Specific communication actions towards the pilot community and the staff of the airline’s operations centre Face to face communication by the project leader
The pilot community will be further made aware during phase during the Pilot/ATCO exchange meetings described above. On Hangar Flying, an article “(Still) going strong: Brussels Airlines and the 737 classic” covering amongs others the continuous descent trials was published 19/5/2011
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B3 SESAR JU PROJECT 6.1.4
OTHER
An article “Continuous Descent Operations” was published on 14th of January 2011 in “Hangar flying” Hangar Flying is a Belgian bilingual monthly aviation luchtvaart-eNews, published the 15th of each month and publicly available on www.hangarflying.be.A small article was also written in the journal “Le Soir” in the beginning of 2011.
6.2
PLANNING OF COMMUNICATION COMMUNICATION ACTIONS AFTER DELIVERY OFPHASE OFPHASE 2
As the final report will be delivered end of December 2011, press activities have been planned for the beginning of 2012: press release, press conference, meetings with local press. Several articles are also planned in the above-mentioned means : publications of Belgocontrol, FABEC, .... To motivate the ATCOs of Belgocontrol to continue the development of CDOs at Brussels Airport, a mousepad with following message will be distributed to APP/ACC ATCOs: Think green, act CDOs. Furthermore, when the pilot/ATCO exchange program (pilots visiting the control centre of Belgocontrol and ATCOs accompanying pilots during Brussels Airlines flights) is approved, the B3-project will be one of the main topics. The pilots and ATCOs will have the possibility to exchange their views and experiences in order to create a better understanding of each other’s work.
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B3 SESAR JU PROJECT List of external communication actions being prepared and planned by the three B3partners: Media
Type of media
Target group
Date
Subject
Press
Press release
External stakeholders
January 2011
Information on the project and on importance of environmental benefits
Meetings with local press
Press
Press External communiqué stakeholders (national, general information press &trade press)
June 2011
Progress of project and first results
Website
Dedicated web External pages on the Stakeholders websites of the 3 parties involved
January 2011
Information on project and progress
Annual 2010
reports Report activities 2010
on External (and April 2011 of internal) stakeholders
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Information on ‘environmental’ performances
B3 SESAR JU PROJECT 7.
TH E FU TURE
7.1
FROM TRIALS TO IMPLEMENTATION IMPLEMENTATION
The aim is to bring the CDO-facilitation from trials into implementation.This means that the facilitation shall be open to all airlines and shall not only be available on runways 25R and 25L but also on the runways 20 and 02.A draft for publication in the AIP is added in appendix 11.
7.2
PROJECT POINT MERGE BRUSSELS
Aside from the CDO-trials in the B3 project, Belgocontrol also studies other options for optimizing vertical profiles, mostly in relation to broader projects. End 2011, Belgocontrol finished a feasibility study on the use of a point merge system for Brussels airport.
7.2.1
PROJECT OBJECTIVES
The Point Merge project for Brussels mainly aims at handling the arrival traffic more efficiently by means of a series of new P-RNAV routes, with the following main project objectives: Enhanced safety, through efficient systemisation of traffic Efficient use of capacity by presenting traffic in more optimised and organised sequences Improved Flight Efficiency and Predictability (minimise the number of track miles flown in EBBU FIR/UIR), by allowing the use of aircraft FMS and associated flight trajectories to the maximum extent Provide P-RNAV route with realistic turns More efficient fuel management by keeping aircraft at higher altitudes in the TMA until their optimum point for descent to the airport â&#x20AC;&#x201C; Phase 2 Version 4.2 - 15/02/2012 - Page 170
B3 SESAR JU PROJECT Enabling Continuous Descent Approaches, thereby giving economic and environmental advantages (reduced noise nuisance and emissions) Reduction of workload for flight crew and air traffic controllers (especially important in the critical arrival phase of flight) Enhanced situational awareness for flight crews and better anticipation of ATC clearances The progressive merging of arrival flows into a runway sequence is often performed in current day operation through the use of open-loop vectoring, air traffic controllers typically issuing a large number of heading, speed and level instructions. This method is highly flexible; however it results in high workload both for flight crews and controllers, and in an intensive use of the R/T. Indeed, it generally requires numerous actions to deviate aircraft from their most direct route for path stretching - and later put them back towards a waypoint or the runway axis for integration. Additionally, it is less efficient for the flight crew or the operation of the aircraft, due to the fact that with open-loop vectors, some parameters are not known, and thus situation awareness is less.. Replacing open-loop vectors by standard flight trajectories increases the efficiency in the ground system: ground-based tools involving trajectory prediction (e.g. conflict detection tools, AMAN, etc.) can be updated more accurately. Finally, implementing a 3D-structure will limit the use of intermediate level offs, because compared to open-loop vectoring the implementation and the fine tuning of the sequence will be easier and more efficient. Under the proposed new “point merge” procedure for integrating arrival flows, the following principles will apply: There will be no change with respect to the ATC goals, which are to enable a safe, expeditious and orderly flow of air traffic. It is expected that there will not be any regulatory issues, in particular regarding ICAO PANS-ATM (Doc 4444). Separation minima - and spacing - will still be based on distance.
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B3 SESAR JU PROJECT The objective is to effectively integrate the arrival flows, while keeping aircraft on lateral navigation, even at high traffic loads. In this context, open-loop radar vectors should only be used to recover from unexpected situations. Delaying or expediting aircraft (through path stretching/shortening) will be performed in a more flexible manner than with current P-RNAV applications in TMA (which are based on a set of pre-defined routes). A key principle is to keep things simple. The new procedure will provide the controllers with a structured and intuitive way of building and maintaining the sequence. The new procedure seeks to decrease the level of ATC intervention, and relies on simple clearances/instructions. In addition to reducing workload, this should diminish the risk of errors and misunderstandings, even in high density TMAs. The procedure should also fit in with well-established air and ground practices and related constraints. In particular, from a cockpit perspective, ‘headsdown’ time should be minimised, especially when aircraft are in the TMA and below FL100.
Based on these principles, the proposed new procedure associates a dedicated route structure with a systemised operating method to integrate arrival flows with extensive use of RNAV. It builds on the following key aspects: Integration of arrival flows is achieved on a common point using ‘Direct To’ instructions. Path stretching is performed without the use of open-loop radar vectors. A “point merge system” is a portion of a route structure, enabling the integration of two or more inbound flows into one sequence, and characterised by the features described below. Traffic integration is performed by merging inbound flows to a single point. After this merge point, aircraft are established on a fixed common route until the exit of the point merge system.
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B3 SESAR JU PROJECT Before the merge point, a ‘sequencing leg’ is dedicated to path stretching/shortening for each inbound flow. While along a sequencing leg, aircraft can be instructed to fly ‘Direct To’ the merge point at any appropriate time (i.e. be kept for a certain amount of time on the leg for path stretching, or inversely sent early direct to the merge point for path shortening). Sequencing legs have a pre-defined length. In order for the controller to easily and intuitively determine the appropriate moment to issue the ‘Direct-To’ instructions for each aircraft, based on its spacing with the preceding aircraft in the sequence, and without requiring the support of any new ground tool, the geometry of the point merge system shall ensure that: Aircraft left flying on a sequencing leg are kept (approximately) at the same distance (‘iso-distance’) from the merge point all along this leg; Distinct sequencing legs are (approximately) located at the same distance from the merge point.
EBBR POINT MERGE
WOODY
PS2 – RWY 25L MOT05 MOT04 WOD01 FL100+
MOT03
TER05
WOD02 ANT
TER04 WESTY
NIK
LEG05
BUN
MOT02
WOD03
YANKI A3000-
TER03 LEG04
CHRLY MOT01
WOD04
LEG03 KERKY
MOTTO FL90-
TER02
BRAVO A4000+
ZULUU BUB
AFI
FLO EASTO TER01
LEG02
TERRY FL90-
NOTE:
HUL
LEG01 FL100+
SLP 230kts IAS @
LGE
WOODY, MOTTO, TERRY and LEGGY
LEGGY
LNO CIV
10
5
0
10 SPI TS 150910
Figure 7-1 - Point Merge System for Arrivals RWY25 Left. – Phase 2 Version 4.2 - 15/02/2012 - Page 173
B3 SESAR JU PROJECT Controller feedback on PMS operations highlighted the following benefits: The noticeable reduction in R/T usage was a significant factor. The systemised nature of PMS approach operations facilitated easy and smooth procedures. The embedded CDA facility in PMS was a bonus. Predictability was improved leading to enhanced situational awareness for controllers and pilots. It was easy to revert to radar vectoring to solve problems.
7.2.2
THE POTENTIAL BENEFITS BENEFITS
7.2.2.1
FOR ATC :
Ability to handle future traffic projections with current staffing levels. More intuitive controller system with increased trajectory predictability enabling better anticipation of traffic evolution. Better task allocation and workload distribution between TMA controllers. Enhanced safety, through efficient systemisation of traffic. Ground system upgrades not required. Standardisation of controller’s performances, thus implying a standard high quality of the traffic management, less conditioned by personal skills. General reduction of controller’s workload in all TMA sectors, since the standardised way of managing the arrival traffic simplifies the work and reduces the need for problem solving, continuous monitoring and R/T communication.
7.2.2.2
FOR THE AIRLINES AND AIRPORT OPERATORS :
Improved flight efficiency and predictability through optimised Flight Management System (FMS) usage. Potential for reduced fuel usage/emissions by enabling Continuous Descent Operations. – Phase 2 Version 4.2 - 15/02/2012 - Page 174
B3 SESAR JU PROJECT Enhanced situational awareness for flight crews. No avionics system upgrades required. Better Collaborative Decision Making (CDM).
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B3 SESAR JU PROJECT
APPENDIC ES
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B3 SESAR JU PROJECT APPENDIX 1 - DEFINITION OF FLIGHT PHASES FOR AIRBUS FMS FMS
Table 0-1 - Flight Phases - Airbus FMS.
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B3 SESAR JU PROJECT APPENDIX 2 – DESCENT PROFILE BASICS. BASICS. VERTICAL FLIGHT PROFILE PROFILE – TYPICAL A typical flight profile consists of: 1. A lateral profile 2. A vertical profile In our B3 concept, focus is on management of the vertical profile.
Typical vertical profile. Within this profile, following flight phases may be distinguished: 1.
Takeoff phase. The takeoff phase extends to the acceleration altitude, e.g. 3.000 ft Above Ground Level. Initially, takeoff thrust (or reduced TO thrust) is set; at the thrust reduction altitude, a climb thrust setting is applied.
2.
Climb phase. The climb phase extends from the acceleration altitude to the topof-climb (TOC) cruise flight level. In an unconstrained situation, using climb thrust, the aircraft will climb at a selected climb IAS until reaching the crossover altitude, from which point a climb Mach will be adhered to. Airspace constraints – Phase 2 Version 4.2 - 15/02/2012 - Page 178
B3 SESAR JU PROJECT may limit the climb speed until passing a designated altitude and/or waypoint. Giving the possibility to the aircraft to climb at its optimal speed and with no step climb till cruising level is an efficient way to save fuel but this should be part of another subject : Continuous Climb Operations (CCO) 3.
Cruise phase. The cruise phase extends from the top-of-climb point to the topof-descent (TOD). The cruise phase can include intermediate climbs as well as en-route descents. These altitude changes are usually performed at cruise speed/Mach. Thrust will be set in order to achieve the selected cruise speed/Mach.
4.
Descent phase. The descent phase starts at the top-of-descent (TOD) point, which is typically less than 200NM from destination. Generally, the engine thrust will be set to idle. Initially, the rate-of descent will be adjusted to achieve a descent Mach; below the crossover altitude, in an unconstrained situation, the rate-of-descent will be adjusted to adhere to a descent IAS. Airspace constraints may limit the selected speed, typically below a designated altitude and/or at a waypoint. Ideally, no intermediate level-off is desired (implicit Continuous Descent Operation – CDO).
5.
Approach phase. The approach phase starts when the approach deceleration point is passed. The deceleration point is computed backwards from the landing point based on optimized flap/slat configuration changes, altitude/speed constraints and flight path.
For each phase of flight, the aircraft operator may define/calculate an “ideal” speed. Application of all these “ideal” speeds will result in an “ideal” flight profile for the aircraft operator. These speeds are often referred as “economical” (or ECON) speeds.
Trip Cost versus Speed.
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B3 SESAR JU PROJECT The “ideal” profile is intended to achieve an optimization of the direct operating cost for a given flight. It may be observed that an operator may deviate from its own “ideal” profile in order to cope with other specific operating/economic conditions. Many parameters do influence the calculated speeds. Hence, even for the same aircraft operator on the same type of aircraft, these speeds may be different for each flight (e.g. due to a different mass of the aircraft)! It should be emphasized that the “ideal” profile will NOT necessarily result in the optimum fuel usage! Generally, a trade-off is made between the fuel-related cost (CF) and the timerelated cost (CT). The ratio between both cost factors is commonly called the Cost Index(CI).
CI =
C Time C Fuel
The Cost Index is an airline depending variable introduced in the Flight Management Computer (FMC) to optimize performance calculations including Mach and step climb optimization. The cost index effectively provides a flexible tool to control fuel burn and trip time between these two extremes. Knowledge of the airline cost structure and operating priorities is essential when aiming to optimize cost by trading increased trip fuel for reduced trip time or vice-versa.
Cost Index values.
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B3 SESAR JU PROJECT Extreme cases: a) CI=0: (when CT=small and CF=large) MINIMUM FUEL STRATEGIC MODE This is the case of highest influence of fuel cost in the operating bill: ECON speeds to minimize consumption in all flight phases: - climb at or about max rate of climb speed - cruise at or about LRC (long range cruise) - descent at speeds close to minimum drag speed b) CI=max: (when CT=large and CF=small) MINIMUM TIME STRATEGIC MODE This is the case when a premium exists on time (arrival); corresponding speeds are then maximal in all flight phases, the FMC defining its own particular VMO/MMOlimits. (VMO = max operating speed / MMO = max operating Mach number) Obviously, the overall shape of the vertical profile will be influenced by the selected speeds for each flight phase. The next figure gives a simplified overall picture. As a result, application of different cost index values will lead to different locations for the topof-climb and top-of-descent points, and fuel burn in the various phases of flight will differ as well. However, note that an operator will strive towards the most economical solution from gate-to-gate which means that he is not primarily interested in the individual figures for each flight phase.
‘Flight efficiency’ may be seen as the degree to which the actually flown flight profile will adhere to the ‘ideally’ planned profile. Each deviation from this profile (theoretically, at least!) will result in a cost penalty. Once a value for the cost index has been determined by the operator for execution of one or more flights, the resulting profile may be called the “airspace user’s preferred trajectory”. This is the starting point for the “business trajectory” philosophy as used by SESAR.
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Impact of the cost index on flight profiles. RELATION TO THE SESAR SESAR – “BUSINESS TRAJECTORY” TRAJECTORY” The four-dimensional (4D) trajectory or ‘business trajectory’ is key to the concept of the future Air Traffic Management (ATM) system being developed by the Single European Sky ATM Research (SESAR) program. Airspace users will agree with Air Navigation Service Providers (ANSPs) and airport operators, from early planning to the day of operations the airspace user’s preferred trajectory for the flight in four dimensions (three spatial dimensions, plus time), where the various constraints of airspace and airport capacity have been fully taken into account. This ‘4D’ trajectory is called the ‘Business trajectory’ in the case of civil aviation and the ‘Mission trajectory’ for military flights, and once agreed it becomes the reference which the airspace user agrees to fly and all the service providers agree to facilitate with their – Phase 2 Version 4.2 - 15/02/2012 - Page 182
B3 SESAR JU PROJECT respective services. From then on, all stakeholders will share information on this 4D Business/Mission trajectory in real time throughout the flight: from preparation through operations to post-disembarking. The “airspace user’s preferred trajectory” is part of the baseline used by the aircraft operator in its negotiations with ANSPs and airport operators in order to obtain a “business trajectory” for a given flight.
THE BACKGROUND Currently, aircraft operators plan each flight in detail and then submit a less detailed flight plan in overview to the relevant air traffic control providers and central flow management unit. The respective air traffic control units then compute these flight plans down to a detailed level in their respective flight data processing systems. These then form the baseline for the voice communication controllers and pilots throughout the flight.
IMPLEMENTING 4D TRAJECTORIES The 4D trajectory concept requires that airspace users be able to agree upon the detailed 4D Business/Mission trajectory directly with the service providers involved in facilitating the flight in the specific airspaces concerned. Detailed positional information for the aircraft throughout the flight will be exchanged with all service providers on the route, as well as ascent and descent paths, and times will be agreed with departure and arrival airports in advance. ATM operations will be automated to a greater extent than currently, with data exchanged directly between the airborne and ground systems. Greater certainty about the positions of every airspace user in the sky at any given moment will improve safety as well as flight predictability. The more efficient resource planning will in turn enable a greater carrying capacity for both airports and the European sky in general.
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4D-trajectory.
DESCENT – GENERAL PRINCIPLES
Descending a (transport) aircraft from its cruising level down to the landing runway of the destination airport is a matter of “energy sharing”. For commercial jet operations, a so-called “Mach/CAS Descent” is usually flown. Ideally, no intermediate level off between top-of-descent and capture of the glide path signal is planned: a Continuous Descent Operation (CDO) at a defined speed, performed in idle thrustconditions is the preferred option. MACH/CAS DESCENT Mach/CAS descents employ a descent speed profile characterized by a constant Mach segment (above the ‘crossover altitude’ – ca. FL290) followed by a constant calibrated
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B3 SESAR JU PROJECT airspeed (CAS)4 segment, performed at idle thrust for maximum fuel efficiency. Mach/CAS descent schedules are typically described in aircraft operating manuals. The Mach/CAS speeds are adjusted to yield optimum fuel efficiency, time efficiency, or (usually) a combination of the two. Airline policies may recommend selected Mach/CAS schedules to suit their specific operational and economic conditions. Below FL100, the ‘ideal’ descent profile may be ‘spoiled’ by altitude/speed constraints imposed by the flown STAR5 and/or terminal airspace regulations.
Simplified descent profile. Figure 3-2 - Simplified descent profile..4 shows a simplified descent profile with various Mach/CAS followed by a standard IAS to final.
The location of the Top-Of-Descent (TOD) point is calculated, taking into account: o The preferred Mach/CAS speed schedule. o The predicted wind profile between cruise altitude and ground level at the destination
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B3 SESAR JU PROJECT airport. o The estimated landing mass of the aircraft. o Deceleration distance to comply with airspace constraints (i.e. max. 250kt IAS below FL100). o Final approach deceleration distance. Note that the descent is performed at idle thrust. Adverse weather conditions may impose a higher than normal idle thrust setting, resulting in a more distant TOD location DESCENT SPEEDS â&#x20AC;&#x201C; EXAMPLE The simulated speed-control process for a representative Mach/CAS schedule of 0.65/280 is illustrated in the following figure. The aircraft, cruising at Mach 0.82 and 35,000 ft, decelerates at cruise altitude to Mach 0.65, with the speed change (Segment 1) complete at a range of about 10 nm. The aircraft maintains this cruise speed until the TOD, at about 34 nm (Segment 2). The aircraft then begins its descent at constant Mach 0.65 to a range of about 61 nm (Segment 3). During the constant-Mach portion of the descent, the CAS gradually increases from 215 kt to 280 kt. At about 23,500 ft, Mach 0.65 is equivalent to 280 kt CAS, and the aircraft switches to descend at constant CAS (Segment 4). At 95 nm, the aircraft has reached 10,000 ft, where it levels-off and decelerates to 250 kt CAS.
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Descent profile. Impact on TAS (True Air Speed) and GS (Ground speed) are not discussed in this section.
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B3 SESAR JU PROJECT IMPACT OF NONNON-ADHERENCE TO THE CALCULATED CALCULATED DESCENT PROFILE PROFILE As seen before, the location of the TOD-point is highly dependent (amongst other parameters) of the desired speed at which the descent is expected to be flown. The desired speed most likely will be the result of a cost calculation, using the appropriate cost index value for the aircraft operator and the subject flight.
Location of the "Top-of-Descent". The ‘optimum’ or ‘ideal’ descent can only be achieved when an unconstrained descent may be flown, starting at the calculated top-of-descent, down to the landing runway. As soon as deviations against this descent path happen, cost penaltieswill occur: 3. Descents performed ‘below’ the intended descent path will result in a time penalty if flown at idle thrust. If thrust is used in such a descent, either during a level-off portion and/or in order to maintain the desired speed, more fuel than anticipated will be burned. This situation may happen when the flight is requested to descent before having reached the optimum TOD-point. – Phase 2 Version 4.2 - 15/02/2012 - Page 188
B3 SESAR JU PROJECT 4. Descents performed ‘above’ the intended descent path will inevitably result in a fuel penalty due to the fuel burned during the extra level segment(s), executed either at cruise altitude, or at any other intermediate altitude. This situation will occur when the flight is requested to maintain the cruise altitude beyond the optimum TOD-point. It is important to realize that the incurred penalty is not related to the descent phase of the flight, but to the direct operating cost of the entire flight. Looking at the descent phase of the flight only, may lead to erroneous conclusions!
TOD penalties. We notice that the higher the cost index: the steeper the descent path (the higher the speed), the shorter the descent distance,the later the top of descent (TOD) point. As for the climb, descent performance is a function of the cost index; indeed, the higher the cost index, the higher the descent speed. But contrary to the climb, the aircraft gross weight and the TOD flight level appear to have a negligible effect on the descent speed computation. Values for time, distance, Mach/CAS, fuel consumption do vary much with flight conditions such as TOD flight level temperature and wind but are less variable with respect to gross weight. Similar to the climb, delta values with regard to time and distance are largely the same whatever the initial flight conditions. – Phase 2 Version 4.2 - 15/02/2012 - Page 189
B3 SESAR JU PROJECT For a typical medium-weight airliner (Airbus A320), we have following values (average takeoff weight):
Table 0-2 - Descent profiles - Airbus A320. These values apply for a descent from FL 370 (ISA conditions, no wind), with a speed restriction of 250kt below FL100. The same values for a heavy-weight airliner (Airbus A330):
Table 0-3 - Descent profiles - Airbus A330. Activation of anti-icing devices has a significant impact on the descent parameters (time/distance profile and fuel consumption) as shown in the following tables (ref. Airbus FCOM).
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B3 SESAR JU PROJECT Airbus A320:
Table 0-4 - Impact of anti-ice and temperature - Airbus A320.
Table 0-5 - Impact of anti-ice and temperature - Airbus A330. Note the impact of temperature deviations. All the above figures do nottake WIND into consideration. The FMS integrates ground speed (i.e. wind) when computing ECON speed/Mach corresponding to a given cost index: headwinds command higher ECON speeds (less exposure time to higher winds) tailwinds command lower ECON speeds (let winds work). Indeed, in the case of headwind, the fuel increment (due to higher speeds) is compensated for by the reduced trip time in terms of cost and vice versa. For all Airbus models, the speed/Mach change is of the order of: • Mach + 0.005 MN for 50kt headwind • Mach - 0.005 MN for 50kt tailwind.
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B3 SESAR JU PROJECT from current position up to 150 NM ahead: actual encountered wind, further up, a wind evolving linearly towards the wind inserted by the pilot into the FMS at that flight level. The nominal flight path (i.e. TOD-point) should not be affected if the wind-corrected ECON speed/Mach is applied. IMPACT ON FUELFUEL-BURN OF A PARTIAL CDO CDO - PROFILE The optimum solution for descent consists in the execution of a continuous descent in idle thrust at the desired speed. Figure 1.12 shows a typical (optimum) descent profile and fuel burn figures for the Airbus A330-300. Any change to this descent profile will result, as seen in the previous section, in a cost and/or fuel penalty. The fuel burn line represents the optimum achievable for descent.
Airbus A330-300 â&#x20AC;&#x201C; M.80/300KT/250KT descent profile and fuel burn. The trial aimed to evaluate the gains obtained by flying part of the descent profile in CDOmode. The CDO-part typically began at altitudes between FL60 and FL150. When the CDOclearance is issued (see next Figure), the subject aircraft was either:
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B3 SESAR JU PROJECT 4) Below the intended descent profile: The aircraft started to descend too early, or descended at higher descent rate than anticipated. Most likely, a level portion of flight was executed below cruise level, resulting in some extra fuel burn. If not, a portion of the descent was flown in idle at a lower speed, resulting in a time penalty. 5) On the intended descent profile: Either the aircraft performed an ‘ideal’ descent, or found itself on the ideal descent path after a portion of level flight. Therefore, even in this case, a fuel penalty versus the optimum descent path cannot be excluded. 6) Above the intended descent profile: The aircraft started too late its descent, or found itself above the ideal descent path after a portion of level flight. Clearly, more fuel than anticipated was burned or more time was spent than anticipated. Clearly, possible gains in fuel burn achieved through the execution of a partial CDO, was biased by extra fuel burn or extra flight time, earlier in the descent phase of flight. Stated differently, the overall fuel burn figure of the flight would dependent of the flown profile before issuance of the CDO clearance.
Initiation of a CDO at or below FL150.
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B3 SESAR JU PROJECT If a continuous descent is initiated at FL150 or below, it is clear that the fuel burn during that phase of flight will be proportional to its duration. The shortest duration will be achieved by aircraft, which are at high speed above their ideal descent path when the CDO-clearance is issued, because they will have to descent faster. Hence their fuel burn will seem optimal, when compared to flights on or below the ideal profile
Example of descent profile and fuel burn below FL150 - Airbus A330-300. Above figure shows a typical descent profile flown by an Airbus A330-300 aircraft below FL150. The vertical profile is shown by the dark blue line, while the thin purple line shows the FCOM-suggested profile. The magenta illustrates the throttle activity: virtually ‘idle’ during the whole descent until capture of the glideslope below 3000 ft. This results in a fuel burn figure (cyan line), which is significantly better than the fuel burn figure given by the FCOM (yellow line). The difference is explained by the fact that the aircraft was flying much faster than normal, resulting in a shorter duration of this phase of flight, and a corresponding fuel “saving” versus the standard. The fact that the aircraft was above its profile at high speed, however, indicated that most likely, extra fuel was burned in the flight phases before passing FL150 in descent. This simple example clearly demonstrates that monitoring of the fuel burn during the CDOportion could obviously lead to wrong conclusions in many cases. Therefore we monitored the fuel burn from TOD until GS-interception. As a consequence however, it was virtually impossible to establish one (or more) baselines. In this project, comparisons were made between declared CDO-flights and other flights, based on an initial assessment of the descent profiles, starting at TOD. Assessment of the – Phase 2 Version 4.2 - 15/02/2012 - Page 194
B3 SESAR JU PROJECT profiles was done using the Eurocontrol Eficat-tool; detailed analysis of the fuel burn figures and engine throttle ‘activity’ relied on FOQA-data of the subject flights.
KNOWLEDGE OF DESCENT PATH BY THE ANSP For the application of CDOs as intended in this program, ATS needed to acquire knowledge about what may be “expected” or is “feasible” for (at least) each aircraft type participating in the CDO-trials. The next figure shows, for a given aircraft type, a “nominal” descent profile and the extreme cases, taking into consideration possible variations of all parameters which have an impact on the overall descent profile.
Different descent profiles. The ‘extreme’ cases define the window or “entry gate” in which the aircraft are expected to arrive, when performing its preferred (or ‘ideal’) descent. In the shown example, the “entry gate” at FL100 is situated between 27 and 45 NM before touchdown. The subject aircraft will need to be at FL100 in descent in order to be able to execute the remaining part of the descent at its preferred speed. Ideally, for the purpose of definition of the “entry gate” at various altitudes, descent profile data (speed, time, fuel, distance to touchdown [or xxx ft] at several altitudes) were to be obtained for (not exhaustive list):
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B3 SESAR JU PROJECT • • • • • • •
“Light” aircraft – Cost index 0. “Heavy” aircraft – Cost index 0. “Light” aircraft – High cost index. “Heavy” aircraft – High cost index. Same profiles for high and low temperature? Same profiles for 50kt headwind/tailwind. ???
Unfortunately, Brussels Airlines does not have the means to calculate the required data the participating airline. A simplified method was used instead. For each aircraft type participating to the trial, a survey of descent profile data, as published in the Flight Crew Operating Handbook, was made. In addition, the descent profile as provided by the Eurocontrol developed BADA-model, was reviewed as well. This figure shows the descent profiles below FL150 for the Airbus A330-300 aircraft. The 3 and 4 degrees slopes are added as a reference.
Descent profiles below FL150 for A330-300.
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B3 SESAR JU PROJECT Analysis of all descent profiles revealed that a 4-degree descent path was flyable for all medium weight (M) category aircraft, while a 3-degree descent path was seen as the limit for a heavy-weight (H) category aircraft.
Difference 3 to 4° glide path.
The 3 and 4-degree rule was used by the Air Traffic Controllers to assess the feasibility and to plan the issuance of a CDO-clearance. The descending aircraft needed to be located either on/below the 3-degree (H), resp. the 4degree (M), slope in order to be eligible for a CDO-clearance. When located above, the Air Traffic Controller inevitably needed to cater for extra track miles in the pattern for allowing a workable descent and approach solution. Obviously, this last scenario needs to be avoided as much as possible.
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APPENDIX APPENDIX 33- DESCENT PRO PROFILES FOR AIRBUS A320 A320 AND A330 AIRCRAFT
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B3 SESAR JU PROJECT APPENDIX 4 – DESCENT SCENARIO – AIRBUS AIRCRAFT. 1. CRUISE DESCENT A cruise descent to a new altitude is initiated by lowering the FCU altitude below the existing cruise altitude when the aircraft is more than 200 NM from the destination, or if a pre-planned step exists (and if the lowered FCU altitude is above FL200 and the highest descent constraint altitude). A managed cruise descent to a new lower cruise altitude results in using an ECON speed profile based on gross weight, cost index, and winds. Once the aircraft is at the new cruise altitude, the cruise flight level is re-established and a newly computed ECON cruise speed/Mach is flown. This results in a smooth transition to the new cruise altitude and speeds. 2. DESCENT TO DESTINATION A descent to the destination (transition to DESCENT flight phase) is initiated by lowering the FCU altitude below the cruise altitude when the aircraft is within 200 NM of the destination and no pre-planned step exists in front of the aircraft. To enter the DESCENT flight phase when the aircraft is more than 200 NM from the destination and above 20,000 ft, momentarily set the FCU altitude to below 20,000 ft, push or pull the ALT select knob on the FCU, and then set and select the desired altitude on the FCU. If the ALT knob is pushed, the aircraft descends at 1000 fpm in vertical speed mode. If the ALT knob is pulled, an open descent is initiated. NOTE:
The above technique can also be used to transition from cruise descent to the DESCENT flight phase.
To return to the CRUISE flight phase when in DESCENT, enter a new cruise altitude on the PROG page that is lower than the aircraft altitude, with the FCU altitude set above 20,000 ft and the highest descent constraint altitude. To return to the CLIMB phase when in DESCENT, enter a new cruise altitude on the PROG page that is higher than the aircraft altitude, with the FCU altitude set above 20,000 ft and the highest descent constraint altitude. A descent to the destination can be either an early descent or late descent, depending on where it is initiated relative to the top-of-descent point. – Phase 2 Version 4.2 - 15/02/2012 - Page 199
B3 SESAR JU PROJECT a) Early Descent/Below Path An early descent (also known as an immediate descent) occurs when a descent to the destination is initiated before the top-of-descent point is sequenced. In early descent (managed flight), the aircraft begins a 1000 fpm vertical speed descent while targeting the descent speed profile (managed mode if the FCU ALT knob is pushed). If speed is managed, managed Mach is flown above the crossover altitude and managed CAS is flown below the crossover altitude. The point where the immediate descent vertical speed path intercepts the FMS-constructed optimum descent path is indicated by a blue lightning bolt on the ND6. If the descent speed limit (or deceleration to the descent speed limit) is encountered while below path in the 1000 fpm descent, the vertical speed is reduced to 500 fpm. The vertical speed descent rate remains at 500 fpm for the duration of the descent as long as this mode is active. The speed targeted is unaffected by the change in the descent rate. If the immediate descent vertical speed path reaches an AT or AT OR ABOVE altitude constraint prior to intercepting the FMS-constructed descent path, the aircraft levels off, proceeds to the constraint in level flight, and resumes the descent upon sequencing the constraint. (This may result in the aircraft recapturing the descent profile, or resuming another vertical speed descent if still below the optimized descent profile.) b) Late Descent/Above Path A late descent occurs when a descent to the destination is initiated after the top-at-descent point is sequenced while in the CLIMB or CRUISE flight phase. The pilot is alerted at the aircraft total energy status by the DECELERATE message on the EFIS and in the MCDU scratch pad if in automatic speed management. NOTE:
The top-at-descent point is displayed only, it engaged in lateral auto control. It is not displayed it engaged in lateral manual control.
In a late descent (managed flight), the aircraft begins an idle thrust descent. If speed is managed, managed Mach is flown above the crossover altitude and managed CAS is flown below the crossover-altitude. When above path, the aircraft accelerates to the descent speed (ECON or pre-selected descent auto speed) plus 20 knots (limited by VMO-3 or MMO-0.0067) to let induced drag and higherspeed facilitate intercepting the vertical profile from above. If a descent speed limit (i.e., 250 knots/10,000 ft) or a speed constraint is encountered, the aircraft is limited to the constraint speed plus 5 knots to re-intercept the path.
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ND = Navigation Display. VMO = maximum operating speed â&#x20AC;&#x201C; MMO = maximum operating Mach number.
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B3 SESAR JU PROJECT When either of these speeds is insufficient to return to the vertical profile two miles before reaching the next AT or AT OR BELOW altitude constraint, the message EXTEND SPD BRK is displayed on the MCDU and the PFD8. In trying to re intercept an FMS profile, a descent to a speed limit or speed constraint can also trigger the EXTEND SPD BRK message. This message always assumesthat the pilot will use at least 1/2 air brakes to meet the constraint. NOTE:
The FMS predictions (especially vertical and performance) require an accurate wind model. Altitude constraints are considered made when the aircraft is within 250 ft.
Descent Path Speed Targets The descent path speed targets are displayed in the following graph:
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B3 SESAR JU PROJECT APPENDIX 5 – AIRBUS A319 - AFM REFERENCE DESCENT DESCENT PROFILES. Airbus A319 – Normal Descent.
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B3 SESAR JU PROJECT APPENDIX 6 – AIRBUS A330A330-300 - AFM REFERENCE DESCENT DESCENT PROFILES. PROFILES.
Airbus A330-300 – Normal Descent.
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B3 SESAR JU PROJECT APPENDIX 7 -DRAFT CDO PUBLICATION VALIDATION DATE OF PREPARATION PREPARATION v.1.0 dd. 17 Dec 2011 EBBR AD 2.21 NOISE ABATEMENT ABATEMENT PROCEDURES
ARRIVAL PROCEDURES Between 2300 and 0459 CDO-facilitation is at ATC discretion or at pilot’s request. Brussels ARR ATIS will broadcast “CDO facilitation on Approach frequency”. Between 0500 and 2259 CDO-facilitation is at ATC discretion only. As soon as practicable after first call on the Approach frequency, ATC shall provide distance-to-go to the runway threshold and an approval to descend at pilot’s discretion. Phraseology “when ready, descend” or “descend at pilot’s discretion”. CDO’s will NOT be facilitated when following conditions apply: • •
adverse weather conditions that may affect the approach (wind shear, thunderstorms, etc) landing runway in use is 07L or 07R.
Subject to ATC instructions, inbound aircraft shall adopt a continuous descent profile – to the greatest possible extent – compatible with safe operation of the aircraft – by employing minimum engine thrust, ideally in a low drag configuration, prior to the FAF/FAP. Note: all noise abatement procedures for arrivals as well as the speed limitations from EBBR AD 2.22FLIGHT PROCEDURES 2.1.3 remain applicable when performing a CDO.
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EBBR AD 2. 24 CHARTS RELATED TO EBBR -
Information box to be added to chart EBBR STAR.01: Continuous Descent Operations (CDO) (see EBBR AD 2.21, § 3.4)
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SLP on AD 2 EBBR-STAR.01 to be removed.
Below the current map AD 2 EBBR STAR.01
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