CANSO Response to IATA User Requirements for Air Traffic Services Report by CANSO

civil air navigation services organisation

CANSO Response to IATA User Requirements for Air Traffic Services Report

Contents

1_ Introduction_p3

4.5_ Microwave Landing System (MLS)_ p10

2_ Summary_p4

4.6_ Non-Directional Beacon (NDB)_ p10

3_ Communications systems and services_p5

4.7_ Tactical Air Navigation (TACAN)_ p11

3.1_ Aeronautical Fixed Telecommunication Network (AFTN) and Aeronautical Message Handling Services (AMHS)_p5

4.8_ VHF Omni-directional Range (VOR)_ p11

3.2_ Very Small Aperture Terminal (VSAT)_ p5

4.10_ Aircraft Based Augmentation System (ABAS)_ p11

3.3_ Air Traffic Services Interfacility Data Communication (AIDC)_ p5 3.4_ VHF Voice 8.33 kHz Channel Spacing_ p5 3.5_ High Frequency (HF) Voice_ p6 3.6_ Satellite Communications (SatCom)_ p6 3.7_ Iridium_ p6

4.9_ Global Navigation Satellite System (GNSS)_ p11

4.11_ Ground Based Augmentation System (GBAS)_ p11 4.12_ Satellite Based Augmentation System (SBAS)_ p11 5_ Surveillance systems and services_p13

3.8_ High Frequency Data Link (HFDL)_ p6

5.1_ Primary Surveillance Radar (PSR)_ p13

3.9_ Aircraft Communications Addressing and Reporting System (ACARS)_ p6

5.2_ Secondary Surveillance Radar (SSR): Mode A/C and Mode S_ p13

3.10_ VHF Data Link (VDL) Mode 2_ p7

5.3_ Precision Approach Radar (PAR)_ p13

3.11_ VHF Data Link (VDL) Mode 3_ p7 3.12_ VHF Data Link (VDL) Mode 4_ p7

5.4_ Automatic Dependent Surveillance – Broadcast (ADS-B) OUT_ p13

3.13_ Controller Pilot Data Link Communications (CPDLC)_ p7

5.5_ Automatic Dependent Surveillance – Broadcast (ADS-B) IN_ p13

3.14_ Pre Departure Clearance (PDC)_ p8

5.6_ Candidate ADS-B Data Links_ p14

3.15_ Digital Automatic Terminal Information Service (D-ATIS)_ p8

5.7_ Automatic Dependent Surveillance – Contract (ADS-C)_ p14

3.16_ Automated Weather Observing System (AWOS)_ p8

5.8_ Traffic Information Service – Broadcast (TIS-B)_ p14

3.17_ Aeronautical Telecommunication Network (ATN) & FANS 1/A_ p8

5.9_ Multilateration (MLAT)/Wide Area Multilateration (WAM)_ p14

4_ Navigation systems and services_p10

6_ Conclusions_p15

4.2_ World Geodetic System–1984 (WGS-84)_ p10

Summary Comparison of CANSO and IATA position - Appendix 1_ p16

4.3_ Distance Measuring Equipment (DME)_ p10

Acronyms Used in this Report Appendix 2_ p18

4.1_ Performance Based Navigation (PBN)_ p10

4.4_ Instrument Landing System (ILS)_ p10

© Copyright CANSO 2010. All rights reserved. No part of this publication may be reproduced, or transmitted in any form, without the prior permission of CANSO. This document has been developed through the collective contributions of CANSO members. The views and recommendations expressed in this publication do not necessarily reflect those of individual CANSO members. We have endeavoured to ensure the integrity of this publication insofar as possible. However, please note that the responsibility for the quality, accuracy, and verification of the data and results in this report rests with participating ANSPs. All recommendations are made without any warranty or guarantee on the part of the contributors or CANSO. CANSO disclaims any liability in connection with the use of this publication or any aspect thereof.

CANSO Response to IATA User Requirements for Air Traffic Services Report

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CANSO Response to IATA User Requirements for Air Traffic Services Report

1 Introduction This document has been written in response to IATA’s Report titled “User Requirements for Air Traffic Services” published 8th May 2009. The aim of this document is to summarise CANSO’s views of the Communication, Navigation and Surveillance (CNS) systems and services discussed in the aforementioned document. Within its membership, CANSO actively encourages global harmonisation of CNS infrastructure but is cognisant of the fact that local requirements may dictate more localised solutions. This is particularly prevalent in the provision of approach and landing systems where requirements can vary for reasons of geography, State regulatory authority intervention through policy, and airport operator commercial considerations. Furthermore, the requirement placed on State regulatory authorities to accommodate a variety of diverse operations in any given piece of airspace will inevitably impact on the provision of CNS infrastructure, which may or may not match the global view. CANSO recognises the SESAR ATM Master Plan as the European high-level reference for the provision of CNS infrastructure for the development of ATM and supports this plan. CANSO acknowledges that there are differences between the global/IATA requirements and those of the SESAR ATM Master Plan but takes the view that they do not differ widely, though for the reasons stated above, we acknowledge that regional requirements may differ from the IATA global view. Notwithstanding, CANSO takes the view that while changes may be required to the ATM Master Plan, we would not anticipate those changes to be on a grand scale. In the vast majority of areas, CANSO’s views and those of IATA are aligned. Where differences between CANSO’s and IATA’s views do exist, they

are raised in the text of this document and the reasons for the variances explained.

2 Summary Below are the systems/services where CANSO’s view differs significantly from IATA’s view: —— Satellite Based Augmentation System (SBAS) —— Primary Surveillance Radar (PSR) Below are the systems/services where the IATA view is broadly in line with CANSO’s view, with minor differences: —— ATS Interfacility Data Communication (AIDC) —— VHF Omni-directional Range (VOR) —— Ground Based Augmentation System (GBAS) —— Automated Weather Observing System (AWOS) —— Aircraft Based Augmentation System (ABAS) For the remaining systems/services referred to in the IATA position paper, CANSO’s position aligns with that of IATA. A tabular comparison of IATA’s views and those of CANSO is provided in Appendix 1 at the end of this document.

CANSO Response to IATA User Requirements for Air Traffic Services Report

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3 Communications systems and services 3.1_ Aeronautical Fixed Telecommunication Network (AFTN) and Aeronautical Message Handling Services (AMHS) 3.1.1 The Aeronautical Messaging system is a business critical service enabling the exchange of flight planning information and provides communications both nationally and internationally. This is currently provided over the Aeronautical Fixed Telecommunications Network (AFTN). The AFTN has been updated and adapted over the last 50 years and is now considered legacy technology, suffering from restricted bandwidth and obsolete protocols. 3.1.2 Aeronautical Message Handling Service (AMHS) is an upgraded Message Switch, which, in Europe, will be implemented on an Internet Protocol (IP) network. 3.1.3 CANSO supports IATA’s position that AFTN be decommissioned and replaced by AMHS. However, it is aware that at least one of its members has no plans for an early migration to AMHS on the grounds that such a move would be driven by a need to support standardised connectivity internationally with neighbouring ANS Providers and to perform advanced communications that are not currently supported by AFTN or other networks. 3.2_ Very Small Aperture Terminal (VSAT) 3.2.1 VSATs are typically used for communications between ATC centres in areas where leased circuits are unreliable or uneconomical. 3.2.2 IATA’s view is that VSAT shall be used where there is no alternative to expand existing networks to that area. CANSO concurs with that position.

3.3_ Air Traffic Services Interfacility Data Communication (AIDC) 3.3.1 Air Traffic Services Interfacility Data Communication (AIDC) is an application for Air Traffic Control use, which has been standardised for use over the ATN network and the legacy AFTN. 3.3.2 In Europe it is legislated to introduce the Internet protocol (IP)-based flight message transfer protocol (FMTP) (OLDI over IP). FMTP has been designed, standardised and implemented as the format for notification, coordination and transfer of flight messages. 3.3.3 Acknowledging that IATA supports AIDC deployment as the primary means of coordination between ATC facilities; CANSO’s view is that while a number of its members support the use of AIDC it cannot fully support IATA’s line on the grounds that Europe has already decided to use FMTP as a successor to OLDI. CANSO would, therefore, welcome IATA support for a broader application of FMTP consistent with the ICAO FFICE. 3.4_ VHF Voice 8.33 kHz Channel Spacing 3.4.1 With the amount of suitable spectrum for voice communications rapidly decreasing, the radio frequency spectrum needs to be used in a more efficient way to ensure that vital services can be sustained. As such, the channel bandwidth for VHF analogue radios has been reduced to 8.33 kHz to provide more channels for communication. 3.4.2 IATA supports the implementation of 8.33 kHz channel spacing. CANSO is in agreement with this position and given the increasing demand on the VHF spectrum would support a future

mandate for 8.33 kHz channel spacing below FL195 in addition to existing mandates above this flight level. 3.5_ High Frequency (HF) Voice 3.5.1 VHF frequencies are adequate for communications within line of sight but do not provide the range required for ATC communications in oceanic and remote airspace. 3.5.2 HF frequencies have a much longer wavelength than VHF and as such, using HF for voice communications provides a vastly increased range over VHF. This makes it suitable for communications in oceanic and remote airspace. The quality of HF voice communications, however, is poor and can lead to ATC instructions being misheard or missed. 3.5.3 CANSO supports IATA’s view that HF voice should be provided and preserved as a backup to data link that would become the primary means of communication in oceanic and remote airspaces. 3.6_ Satellite Communications (SatCom) 3.6.1 Satellite communications (SatCom) are used by ATC to provide a direct communications link between controller and pilot as opposed to 3rd party HF voice messaging. SatCom are used for communications in oceanic and remote airspaces. SatCom are clearer and more reliable than HF but come at greater cost. 3.6.2 IATA supports SatCom to enable data communications in oceanic and remote airspaces. CANSO concurs with this view but would seek to use lower cost alternatives where terrestrial coverage is available (e.g. VDL etc).

3.7_ Iridium 3.7.1 The IRIDIUM satellite network provides an alternative to the INMARSAT SatCom network and provides coverage to the Polar Regions where INMARSAT does not. 3.7.2 ICAO is currently working on approval of IRIDIUM for safety of flight services by ATC and therefore CANSO supports the use of technology and associated avionics. 3.8_ High Frequency Data Link (HFDL) 3.8.1 Whilst CANSO supports the view that there is a requirement for a data link service in oceanic and remote airspaces, SatCom is recognised as the preferred medium for data link. 3.9_ Aircraft Communications Addressing and Reporting System (ACARS) 3.9.1 ACARS currently provides widespread communications between airlines and their fleets for airline operational purposes. It is also used for some limited ATC applications. FANS-1/A uses an enhanced version of the existing ACARS ground networks to provide an ADS-C and CPDLC capability for ATC purposes. 3.9.2 IATA states that it “supports upgrade to a full-bit orientated service while continuing to use ACARS as a basis for transition”. 3.9.3 CANSO supports the use of datalink over the ACARS network. It also accepts the use of ACARS for time/non-mission critical traffic; however, it considers that, where necessary, it should meet the minimum performance standards published in the GOLD (Global Operational Datalink) Manual. Where performance does not meet these standards, the infrastructure should be

CANSO Response to IATA User Requirements for Air Traffic Services Report

upgraded and the protocols enhanced to provide time/mission critical communications. 3.10_ VHF Data Link (VDL) Mode 2 3.10.1 VDL Mode 2 is an air-ground data link. VDL Mode 2 has been recognised as the network to support ATN and ICAO CNS/ATM concept. CANSO is committed to achieving the 2013 EU mandate for implementing VDL Mode 2 datalink. 3.10.2 VDL Mode 2 is an air-ground data link using 25 kHz channels and is an upgrade of the existing ACARS network. The advantage of VDL-2 compared with ACARS is the data rate; VDL-2 delivers data at 31.5 Kbps whereas ACARS delivers data at 2.4 Kbps. This is a superior technology as it results in reduced message delay and achieves higher success rates under heavy usage. 3.10.3_ CANSO concurs with IATA’s support for the use of VDL Mode 2. 3.11_ VHF Data Link (VDL) Mode 3 3.11.1 VDL Mode 3 is an alternative proposal to 8.33 kHz channel spacing. Airlines operating internationally are against the need for multiple equipment carriage to serve the same purpose and so IATA does not support VDL Mode 3 deployment. CANSO is also of this view on the grounds that 8.33 kHz channel spacing has been implemented in Europe. 3.12_ VHF Data Link (VDL) Mode 4 3.12.1 VDL Mode 4 is a data link technology designed to support CNS/ATM digital communications services. For communications purposes, this was considered a candidate for

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point-to-point datalink in support of advanced applications. For surveillance, VDL Mode 4 was an alternative ADS-B datalink to 1090 extended squitter (ES). 3.12.2 IATA does not support VDL Mode 4 deployment as “1090 MHz Mode S Extended Squitter (ES) has been chosen as the standard for international aviation.” CANSO concurs with this position but acknowledges that there may be some ANSPs that will take the view that they would never automatically exclude consideration of the use of VDL Mode 4 if it could be shown that its deployment was in line with operational requirements and that it provided added value to the overall system. 3.13_ Controller Pilot Data Link Communications (CPDLC) 3.13.1 CPDLC allow controllers to communicate with aircrew using a text based digital message. Where there has been an increase in the radio communications required, due to increased sectorisation for example, CPDLC has the potential to allow controllers to reduce the number of radio voice communications, which are made. 3.13.2 CPDLC also has the potential to reduce controller workload and the demands on the radio frequency spectrum, as well as the potential to reduce risk caused by potential misunderstandings of voice communications. 3.13.3 IATA “supports CPDLC deployment as the primary means of communication in oceanic and remote airspace… CPDLC should be gradually introduced to busier en-route terminal airspace.” 3.13.4 CANSO concurs with the IATA position and supports the use of CPDLC

while maintaining the requirement for voice communications as a back up for non-routine communications.

3.16.2 Weather observations were initially in the form of METARS. This was done by manned observation. This service is now becoming more automated to increase efficiency and reduce cost.

3.14_ Pre Departure Clearance (PDC) 3.14.1 Also known as Departure Clearance Service (DCL), this provides a service for the use of automated requesting and delivery of departure information and clearance. This is sent to the aircraft using the Aircraft Communications Addressing and Reporting System (ACARS). It is not currently part of the Data Link Services mandate. IATA supports the use of PDC and CANSO concurs with this view. 3.15_ Digital Automatic Terminal Information Service (D-ATIS) 3.15.1 D-ATIS allows operational information to be sent to the aircraft via a datalink, thus easing the pressure on the radio frequency spectrum and reducing the work load of the aircrew as the information is displayed in data form in the cockpit and this information can be recalled as and when it is needed. 3.15.2 IATA’s view is that “D-ATIS should be deployed at major international airports while providing dual-stack support during transition from ATIS to D-ATIS.” CANSO understands this to mean that during the transition period, legacy voice ATIS will be maintained. In this regard, CANSO concurs with IATA’s view. 3.16_ Automated Weather Observing System (AWOS) 3.16.1 Weather forecasts are needed both by ATC and the airlines. Changes in weather can affect the time of arrival at an airport potentially resulting in delays. This needs to be minimised as much as possible.

3.16.3 The system used predominantly for Meteorological services is the Semi- Automated Meteorological Observing System (SAMOS). SAMOS provides an ATIS, which can then be communicated to the aircraft. 3.15.4 CANSO supports IATA’s position that AWOS should be implemented “where operationally justified and cost-effective…” but currently does not anticipate any plans to replace SAMOS. 3.17_ Aeronautical Telecommunication Network (ATN) & FANS 1/A 3.17.1 The ATN is a highly meshed network for providing aeronautical messages such as flight plans and Met information. The ATN comprises both air-ground and ground-ground communications networks. It is a global data network designed to connect those playing a role in air transport and is used by the Aeronautical Message Handling Service (AMHS) application to provide a message service. 3.17.2 ATN is based on the ISO 7-layer stack principle, incorporating a dynamic routing protocol similar to Open Shortest Path First (OSPF) used in IP networks. This leads to improved speed and data integrity compared to ACARS. This provides a faster service and improved integrity. CANSO supports a transition to VDL-2 over ATN for all aircraft in the long term but recognises that the evolution to ATN will be driven by the need to support applications/ technologies such as VDL-2 and that the timing of the transition to the ATN will evolve as the need for the applications becomes essential.

CANSO Response to IATA User Requirements for Air Traffic Services Report

3.17.3 FANS is an alternative solution to ATN. FANS is an integrated system including hardware, software and communication networks, pilots and controllers and the procedures for use by pilots and controllers. FANS can provide both ATC and airline administrative capabilities worldwide. It uses both satellite and VHF communication technology. FANS 1 is the Boeing system and FANS A is the Airbus system. 3.17.4 CANSO recognises that the FANS network has limitations in domestic airspace and that ATN is the preferred solution. However, FANS is considered well suited to operations in oceanic and remote airspace. ATN would need to support ADS-C if it were decided to cease to support FANS 1/A in oceanic and remote airspace. ATS provider States will support FANS operations for the foreseeable future.

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4 Navigation systems and services 4.1_ Performance Based Navigation (PBN) 4.1.1 Performance based navigation (PBN) is a global set of navigation specifications defined by ICAO based on a level of navigation performance. This performance is defined in terms of accuracy, integrity, continuity, availability and functionality. 4.1.2 CANSO supports the PBN concept and the design of airspace based on the operation of aircraft equipped to RNP/RNAV navigation specifications. This, along with implementation of Approach Procedure with Vertical guidance (APV), will facilitate the rationalisation of the groundbased navigation infrastructure as part of an overall strategy to reduce the cost of navigation service provision. 4.2_ World Geodetic System – 1984 (WGS-84) 4.2.1 WGS-84 is a standard to provide a reference to terrain and charting. The ICAO standard states “World Geodetic System – 1984 (WGS-84) shall be used as the horizontal (geodetic) reference system for air navigation.” The Global Navigation Satellite System (GNSS) and aircraft navigation and terrain avoidance systems are based on WGS-84. 4.2.2 IATA states “Implementation and maintenance of WGS-84 coordinates is a paramount priority due to consequential safety implications”. CANSO supports this view. 4.3_ Distance Measuring Equipment (DME) 4.3.1 DME measures distance by timing the difference between signals being sent and received. The aircraft sends out interrogations and the ground DME transponder replies with a precise turn-around time delay. The time between an interrogation and the reply is then calculated.

4.3.2 IATA “supports DME deployment where required as a contingency navigation system to GNSS and in accordance with an agreed airspace concept.” CANSO supports this view. 4.4_ Instrument Landing System (ILS) 4.4.1 ILS is a precision final approach system providing aircraft with lateral and vertical guidance. 4.4.2 IATA states “when… GBAS becomes a viable option for CAT II/III approaches, then there should be a transition to replace ILS with GNSS Landing System (GLS).” CANSO agrees with this view but recognises that there are commercial matters to consider in the provision of instrument landing systems, which meet the needs of all customers. 4.5_ Microwave Landing System (MLS) 4.5.1 MLS is a potential replacement system for ILS. MLS can provide guidance in low visibility conditions and can be used to enable closely spaced auto-land approaches. MLS eliminates the problems with FM broadcasting interference experienced by ILS. Another advantage of MLS is that it has the potential to enable curved approaches. 4.5.2 IATA states “ANSPs/States should only consider MLS implementation at specific aerodromes and these should be limited to places where the airspace users are wiling and able to equip and fund for its installation.” CANSO is in agreement with IATA’s view in this regard. 4.6_ Non-Directional Beacon (NDB) 4.6.1 Automatic Direction Finding (ADF) Equipment onboard the aircraft is able to

CANSO Response to IATA User Requirements for Air Traffic Services Report

determine the bearing of an NDB relative to the aircraft. NDBs do not provide input to RNAV systems and are therefore outside of the scope of PBN. 4.6.2 While CANSO supports IATA’s view to “transition to GNSS as the primary radio navigation aid and recommend rapid decommission of NDBs for navigation services”, it does not support the proposed timeline as it recognises that there are commercial pressures on ANS providers and airport operators to provide services for certain customers which may lead to the prolonged use of NDB in remote areas and at smaller regional airports. 4.7_ Tactical Air Navigation (TACAN) 4.7.1 IATA’s position is that “there are no civil aviation requirements for TACAN.” TACAN is a military ground-based navigation aid and as such, CANSO takes no view as to its use though it notes that appropriately certified TACANS are currently utilised in some navigation databases to provide part of position information required by either the ground-based or RNAV system. 4.8_ VHF Omni-directional Range (VOR) 4.8.1 IATA recommends a target withdrawal date of 2016 for VOR. While CANSO agrees that VOR should ultimately be withdrawn from service as it is commercially beneficial to do so, it recognises that the transitional phase will, inevitably, be longer than that envisaged by IATA and that many, if not all ANSPs will justify maintaining a back-up network of VORs (and DMEs) to provide RNAV 5 coverage in the event of a total satellite system outage. This requirement is likely to disappear when a fully operational second global navigation satellite system becomes available. However, it is realistic to expect that VORs will be in operation until circa 2030.

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4.9_ Global Navigation Satellite System (GNSS) 4.9.1 Global Navigation Satellite Systems are currently in use with new regional and select ANSP systems coming on line in the near future. GNSS is broadly viewed as the replacement system for fragmented terrestrial navigation systems in use today. CANSO supports the use of GNSS. 4.10_ Aircraft Based Augmentation System (ABAS) 4.10.1 IATA states, “with the exception of GBAS for precision approach, ABAS is the preferred and most cost-effective system for augmenting the accuracy, integrity, availability, and continuity of the GNSS signal.” CANSO broadly agrees with this statement and takes the view that where aircraft are already equipped, ABAS is a cost-effective system providing integrity monitoring for APV and en-route navigation. 4.11_ Ground Based Augmentation System (GBAS) 4.11.1 CANSO’s view is that the decision whether to utilise GBAS in preference to SBAS or any other landing aid, will be based on the commercial considerations of the airport operator or the organisation responsible for providing such services and supported by a cost-benefit analysis. 4.12_ Satellite Based Augmentation System (SBAS) 4.12.1 Satellite Based Augmentation Systems (SBAS) are systems that augment Global Navigation Satellite Systems (GNSS) to improve the accuracy and integrity of the positioning signal. The user may require avionics changes to be capable of using the system. SBAS could be a cost effective upgrade path for airports that do not currently operate an Instrument Landing System (ILS).

4.12.2 IATA states it “does not support the continued investment, development, and implementation of SBAS… this is the only GNSS augmentation system that airlines are not willing to pay for cost recovery.” 4.12.3 Many commercial aircraft are equipped with a Baro-VNAV capability, one means of supporting APV. Presumably, it is for this reason that IATA sees no benefit in SBAS. However, many low end users including General Aviation do not, and could not, easily equip to provide a Baro-VNAV capability. SBAS, the other means of supporting APV, is a cost effective means of equipage to gain the advantages of APV for “low end” airspace users. 4.12.4 CANSO supports the use of SBAS at airfields where there are NDBs/VORs used as part of an approach procedure, as SBAS could provide an alternative approach and facilitate the removal of these beacons VOR. However, it recognises that those responsible for the provision of landing services at airports have to consider the requirement of their customers and base their decision on what final approach aid to provide on a sound business case.

CANSO Response to IATA User Requirements for Air Traffic Services Report

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5 Surveillance systems and services 5.1_ Primary Surveillance Radar (PSR) 5.1.1 IATA states, “Currently there is no airline requirement for using this technology.” CANSO’s view is that there is still a requirement for Independent Non-Cooperative surveillance as long as unacceptable risks exist from aircraft operating without transponders. 5.1.2 IATA states that, “Multilateration will be a superior replacement for PSR in terminal airspace.” CANSO’s view is that Multilateration (MLAT) (also known as Wide Area Multilateration (WAM)), ADS-B and Mode S SSR are replacements for “traditional SSR” and are not replacements for PSR. There is an ongoing need for independent non-cooperative surveillance in many TMAs to be able to detect aircraft which are not equipped with Mode S transponders or who have suffered a transponder failure. Additionally, General Aviation (GA) aircraft periodically infringe upon controlled airspace. Many of these aircraft are not equipped with transponders as carriage is not a mandatory requirement. Therefore, in an environment with no PSR it would not be possible for these aircraft to be detected by controllers and could lead to potentially serious consequences. 5.1.3 Multi-Static PSR (MSPSR) is a technology that CANSO supports. It could fulfil the requirements that are currently achieved using PSR but in a more cost-effective manner. 5.2_ Secondary Surveillance Radar (SSR): Mode A/C and Mode S 5.2.1 SSR is an independent cooperative surveillance system. The SSR sends out an interrogation to which the aircraft’s transponder replies. Traditionally this transponder was Mode A/C. Mode A broadcasts the aircraft’s identity and Mode C provides the pressure altitude. Mode A/C

is limited in capacity and is only able to provide 4096 unique identities. CANSO supports the continued use of SSR until it is replaced by Mode S equipment. 5.2.2 CANSO supports the use of Mode S over Mode A/C due to the increased number of aircraft parameters which are downlinked from the aircraft. This position is in concurrence with IATA’s view. 5.3_ Precision Approach Radar (PAR) 5.3.1 IATA’s position on PAR is that “there is no airline requirement for PAR.” CANSO agrees with this statement. 5.4_ Automatic Dependent Surveillance – Broadcast (ADS-B) OUT 5.4.1 An aircraft equipped with ADS-B OUT automatically broadcasts its position, velocity, identification and other aircraft data. These broadcasts are received on the ground, processed and displayed on the controller’s screen. 5.4.2 On the basis that there will ultimately be a network of ADS-B receivers/WAM stations which could eventually replace radar, CANSO agrees with IATA and supports the use of ADS-B OUT. 5.5_ Automatic Dependent Surveillance – Broadcast (ADS-B) IN 5.5.1 ADS-B IN is a surveillance technology which will increase pilot situational awareness. Aircraft equipped will be able to broadcast and receive ADS-B data. This allows the pilot to have improved situational awareness and ultimately may lead to aircraft being able to self-separate using ADS-B data.

5.5.2 The development of ADS-B IN will allow the implementation of advanced ATM concepts aimed at reducing controller workload thus enabling the possibility to handle increased traffic numbers. 5.5.3 CANSO supports the eventual transition to ADS-B IN to provide greater pilot situational awareness and to enable future ATM concepts such as ASAS, to increase capacity but concurs with IATA’s view that global consensus must be reached on the operating concept and that a positive business case must be produced.

5.8_ Traffic Information Service – Broadcast (TIS-B) 5.8.1 TIS-B provides an air traffic surveillance picture to the aircraft, transmitted from ground stations using data link. TIS-B is able to support the provision of a complete surveillance picture and as such could be used to transition to a full ADS-B equipage. 5.8.2 IATA states, “If a single standard is not implemented, then ADS-B IN systems will require TIS-B functionality to display all aircraft of relevance in any given traffic situation.” CANSO supports this view.

5.6_ Candidate ADS-B Data Links 5.6.1 There were three data links considered and ICAO formalised standards for these. The data links considered for ADS-B are: 1090 MHz Mode S Extended Squitter (1090 ES), VDL Mode 4 and Universal Access Transceiver (UAT). 5.6.2 CANSO concurs with the IATA view that 1090 ES should be used as the supporting datalink for ADS-B applications. 5.7_ Automatic Dependent Surveillance – Contract (ADS-C) 5.7.1 ADS-C is used as a surveillance technology in oceanic and remote airspace. With an ADS-C system a message is sent from the aircraft at pre-determined intervals. This interval is set in the ground system based on a requirement to meet an agreed level of safety for the operation. 5.7.2 CANSO supports the view of IATA that ADS-C should be used for surveillance in oceanic airspace where appropriate.

5.9_ Multilateration (MLAT)/Wide Area Multilateration (WAM) 5.9.1 MLAT/WAM is a form of co-operative independent surveillance. This is because it relies on signals being transmitted from the aircraft which are received by ground stations. MLAT can receive ADS-B, Mode S or SSR transmissions. 5.9.2 The ground stations triangulate to calculate a position for the aircraft – a central processing unit calculates the aircraft’s position from the time difference of arrival (TDOA) of the signal at the different antennas. 5.9.3 CANSO supports IATA’s view to utilise MLAT/WAM to meet specific surveillance requirements when supported by operational requirements and a cost benefit analysis.

CANSO Response to IATA User Requirements for Air Traffic Services Report

6 Conclusions The preceding text and Appendix 1 (see page 16) illustrates that there are many systems and services where the views of CANSO and IATA are aligned. For some of the systems and services the views of CANSO and IATA are broadly in-line but with minor differences. These systems/services are: —— ATS Interfacility Data Communications (AIDC) —— VOR —— ABAS —— GBAS —— AWOS The views of IATA and CANSO do not align in respect of PSR and SBAS: CANSO notes that IATA does not support either of these systems and does not wish to pay for their maintenance and implementation.

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Appendix 1 - Summary Comparison of CANSO and IATA Position IATA’s Position Technologies and applications

Support where justified

AFTN

Maintain during transition

Do NOT support or support in limited cases

AMHS

VSAT

AIDC

VHF Voice 8.33 KHz X Channel Spacing

Communications

Navigation

HF Voice

SatCom

IRIDIUM

HFDL

ACARS

VDL Mode 2

VDL Mode 3

VDL Mode 4

CPDLC

ATN

To be Determined

PBN

WGS-84

Essential

DME

ILS

MLS

NDB

TACAN

VOR

GNSS

ABAS

GBAS

SBAS

Alignment with CANSO’s Position

CANSO Response to IATA User Requirements for Air Traffic Services Report

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IATA’s Position Technologies and applications

Support where justified

Maintain during transition

PSR

SSR Mode A/C SSR Mode S

X X

PAR Surveillance

ADS-B OUT

ADS-B IN

ADS-C

TIS-B

Candidate ADS-B Data Links