17 minute read
Safety Accident Analysis Just enough vs. just too little
Having sufficient fuel cannot be stressed enough. However, adding that bit extra also has its place. Steve Ayres examines recent accidents that show how handling an emergency is much more challenging when you know you are also running out of fuel…
We have probably all, at one time or another, been a bit tighter on fuel than we would have liked. It is a distraction, can be stressful and certainly makes the trip less pleasant than it should have been. Even though everything eventually ends well, we know the margin for error was much reduced. In this month’s accidents, that margin was eroded to such an extent that when something else did go wrong the pilot was left with very few options. Stressed, distracted and now under time pressure, decision making is at its worst and in these instances, bad decisions ultimately proved fatal.
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Accident 1
The pilot and his son were relocating the aeroplane, a Cessna 150H, from New York to Festus Memorial Airport (FES), Festus, Missouri, a total distance of some 800nm. Fuel receipts showed that the pilot refuelled the aeroplane three times during the trip. The third refuelling stop was at Greensburg Municipal Airport (I34), Greensburg, Indiana, where the aeroplane was fuelled with 13.62 gallons at 1906, a distance of some 275 miles from the final destination airport.
The pilot and passenger communicated with the pilot’s fiancée via text message during the trip. They told her that the aeroplane was experiencing a ‘small electrical problem’ and stated that their estimated time of arrival (ETA) would be determined ‘at the next fuel stop... just before dark’. After their final fuel stop they estimated their ETA at FES would be about 2215. They then asked her to stand on the end of the runway with a flashlight to help guide the aeroplane in for landing. They also stated that they would attempt to activate the airport lighting system with a handheld radio, but they were unsure if the radio had enough battery power to perform the task. During the last leg of the flight, they indicated that they had ‘picked up a head wind’ and further extended their ETA by five minutes.
The pilot’s fiancée reported that she went to the end of the runway with the flashlight on, and the pilot attempted to land, but she was unsure if the aeroplane touched down on the runway due to the dark/night conditions. She further reported that the aeroplane was ‘blacked out’ and did not have any exterior lights on. The last text message from the pilot stated, ‘keep light on’. After several minutes of not seeing or hearing the aeroplane, she tried contacting the pilot multiple times, but with no response, before contacting law enforcement. The wreckage was located the following morning in a tree-covered swamp about 1/4 mile south-east of the departure end of Runway 19 about 440ft above mean sea level.
At the time of the accident, the pilot was employed as an airline pilot. He previously worked as a helicopter air ambulance pilot and a military helicopter pilot. The pilot held a mechanic certificate with airframe and powerplant ratings.
The Cessna 150H pilot’s operating handbook (POH) stated that the maximum capacity for both fuel tanks was 26 gallons total (13 gallons in each tank). The POH further stated that the usable fuel amount for all flight conditions was 22.5 gallons total, and the unusable fuel amount was 3.5 gallons total.
The Textron Aviation Pilot Safety and Warning Supplements discussed electrical power failures. This document states in part: The pilot should maintain control of the aeroplane and land when practical if an electrical power loss is evident. If an electrical power loss is experienced, continued flight is possible, but should be terminated as soon as practical. Such things as fuel quantity and engine temperature indicators and panel lights may no longer work.
According to information from the US Naval Observatory, sunset at FES on the day of the accident occurred at 1902, and the end of civil twilight was 1928.
The airport lighting system at FES comprised runway edge lights (medium intensity runway lights) and runway end identifier lights. A pilot could activate the lighting system while airborne by keying the aircraft’s microphone on the airport’s common traffic advisory frequency. The FES runway lighting system could also be manually activated by a switch on the outside of the main hangar. No malfunctions or failures of the airport lighting system were listed for FES.
Flight control continuity was established for the airframe. All structural components of the aeroplane were located at the accident site. The aeroplane sustained substantial damage to both wings, the fuselage, and the empennage. Both wings sustained substantial impact damage from contact with trees. The fuel tanks remained intact, and a total of about 2.25 gallons of fuel were extracted from the two fuel tanks.
The propeller blades did not exhibit chordwise scratches or torsional deformation and the engine was therefore unlikely to have been rotating at the time of impact.
The alternator and the voltage regulator were examined and functionally checked. The alternator performed normally with no malfunctions or failures. The voltage regulator was inoperable and it was manufactured around 1976.
There was no life limit or replacement interval specified. Review of the aeroplane’s maintenance records did not indicate how long the voltage regulator had been installed on the accident aeroplane.
Accident 2
On arriving at his destination airfield in daytime Visual Meteorological Conditions the pilot of a pressurised Cessna P210 Centurion transmitted, “We don’t have a green light on our gear down here, we might have to circle if ya don’t mind?” The Tower controller offered to observe the landing gear position if the pilot made a low-altitude flyby over Runway 33. The pilot replied, “All right, looks like we’re partial down, I just don’t think we’re all the way down, I’ll try to cycle it again, we’re coming over.” Just over a minute later, the pilot transmitted, “We got a partial down, Tower, but it’s not all the way down, we don’t have a green light.” At that time, the aeroplane was on a one mile final approach for Runway 33.
The pilot then conducted a low pass over Runway 33, during which the controller reported that the right main landing gear appeared to be ‘still up’. The pilot indicated that he was going to attempt to recycle the gear and would make a left turn to remain in the airport traffic pattern.
Almost five minutes later, the pilot transmitted, “Doesn’t appear we’re making any progress with the gear whatsoever.” The controller asked what the pilot’s intentions were.
The pilot replied, “Well, if we can’t make anything happen, I guess we can land in the grass just, uh, on the infield there, just parallel with three three, huh?”
The controller stated that he would prefer the aeroplane to land on Runway 7/25 and that he could not clear the aeroplane to land in the grass.
The pilot asked the controller, “So, the west side of one five is not good in the grass?” The controller replied, “I can’t clear you for a landing there, but you, if that’s where you have to put it down, that would be, uh, ya think it would be better to land in the grass than on the runway?” At that point, the aeroplane had climbed to 2,500ft msl and was flying northbound, parallel to Runway 33. The pilot then asked the controller, “Ya want me on seven?” The controller subsequently cleared the pilot to land on Runway 7, adding that the pilot could keep circling while he arranged for airport fire rescue equipment to meet the aeroplane on the runway. At that point, some seven minutes after first mentioning the undercarriage problem, the aircraft ran out of fuel and crashed in a residential area just outside the airfield boundary.
Ayres’ Analysis
As someone who, in a former life, frequently walked out to his aeroplane already primed with the knowledge that fuel for the sortie was going to be tight, I know how such thoughts can play on the mind. Sure, through training we can learn to control the preoccupation that such concerns bring. In the same way a military pilot flying from a carrier will always be preoccupied with thoughts of finding the carrier for that final landing. But, even in the best of circumstances, being short of fuel messes with your head. It adds pressure to what should be routine and can stress out the most capable pilot, such that when confronted by a new challenge they are already functioning at the limit of their capacity, and any chance of rational thought has long departed.
This couldn’t be better illustrated than by these accidents. It is difficult to imagine what was going through the pilot’s mind in the first accident when he took off with a known electrical problem for a night transit in which he was going to require enough power to operate the radio controlled landing light system at his arrival airport (although, it could apparently be activated from outside a hangar).
We can only surmise that his military helicopter experience gave him a degree of confidence that landing by the light of a torch beam was feasible. In the end though it was a lack of fuel that backed him into a corner from which there was no way out and subsequent loss of control during a night forced landing proved fatal for both occupants.
In the second of the accidents, I make no excuse for using a portion of the transcript from the accident first highlighted in last month’s Accident Reports. It makes harrowing reading but illustrates how preoccupation with a seemingly serious malfunction can be a total distraction from something far worse. Deciding to ‘crash-land’ in a controlled fashion is always preferable to being forced to do so when the fuel runs out.
As always, if everything had ‘gone to plan’ in these flights none of these accidents would have happened. Sure, there would have been some bar-chat about being a ‘bit tight on fuel’, mutterings of ‘stronger headwinds than expected’ etc. In the end, though, there was no banter and no happy endings. What should have been perfectly manageable and survivable emergencies turned into fatal accidents, for the most part, because of insufficient fuel when the unplanned-for happened.
Flying has a habit of throwing the unforeseen at us and just when we think things can’t get any worse they sometimes do. However, adding low fuel into the mix is certain to increase the heart rate even though it is almost always avoidable. Having insufficient fuel to properly deal with an emergency such as the gear failing to deploy, runway lights not working, baulked approach or bad weather at the destination is foolhardy. Add in the pucker-factor that running short of fuel gives, and the likelihood of dealing effectively with a separate emergency will go out the window. Yes, it is a double emergency but largely of our own making and let’s face it, not really ‘unforeseeable’. So, fill up – and if necessary divert in time!
Safety Accident Reports
No control
Steve Ayres summarises and comments on accident reports from around the world and looks at a wind app which presents a useful graphical forecast of winds across the UK for the week ahead…
Out of control
Cessna 210 VH-SJW Darwin, Northern Territory Injuries: Minor
A Cessna 210M was conducting a charter flight with four passengers from Darwin to Tindal. Soon after departure, the pilot diverted 5nm right of the planned track to avoid a large storm cell that was 5nm left of track. About 10 minutes after departure, while maintaining 3,500ft, the aircraft encountered sudden and sustained severe turbulence, the turbulence penetration speed for the Cessna 210M was 119kt.
The pilot stated that, during the incident, airspeed could not be controlled through changing power settings, and for the most part the airspeed could not be held below 155kt. For extended periods, the pilot had no control over bank angle, height, or heading. At one stage, the airspeed dropped below 140kt, and the pilot lowered the landing gear in order to create drag and slow the aircraft down.
The backrest of the centre row of seats could be folded forwards for access to the rear row of seats, which was standard. One centre row passenger found it difficult to brace against the moveable seat back, and although wearing a seatbelt, reported not being sufficiently secure. This passenger’s neck was injured in the incident.
The turbulence encounter lasted about 3.5 minutes. Radar at Darwin recorded the aircraft’s highest groundspeed as 210kt, and rate of descent at one point to be 5,000fpm with a lowest altitude of 1,200ft. Control of the aircraft was lost for more than three minutes, and three passengers sustained minor injuries.
After landing at Tindal and inspecting the aircraft for potential damage, the pilot ferried the aircraft to Milingimbi Island. At Milingimbi Island, the pilot picked up four more passengers for a charter to Galiwin’ku (Elcho Island). The pilot reported the incident to the operator that evening. Upon receiving notification of the turbulence encounter, the operator grounded VH-SJW at Galiwin’ku, pending an engineering inspection. Comment In this incident, avoiding a storm by more than the recommended separation was not enough to keep the aircraft and its passengers safe. Thankfully, we are unlikely to see storms of this magnitude in the UK, but severe turbulence is not uncommon, so ensuring there are no loose articles and that all the passengers remain strapped in is a must. Inspection of the aircraft ultimately showed no damage but the operator was right to have grounded it, and point out to the pilot that it should not have been flown again following the incident.
Several reasons to fail
Van’s RV-7 ZK-DVS Te Kopuru, Northland, NZ Injuries: Two fatal
Seventeen minutes after departing Whangarei aerodrome, a Van’s RV-7, entered a high angle of bank (AoB) manoeuvre, achieving 70°.
Five seconds later, the AoB increased to 130° and the aircraft began to pitch nose-down. During the resulting descent, the indicated airspeed was recorded at 244kt.
Approximately 30 seconds after entering the high AoB manoeuvre, witnesses observed the aircraft breakup in flight and then impact terrain.
The pilot was appropriately rated and current on the aircraft, having conducted approximately 105 hours on type and approximately 20 hours in the last 90 days.
He had conducted his last Biennial Flight Review (BFR) and the instructor stated that he identified no issues with the way the pilot flew. The BFR was conducted in the accident aeroplane. Both medium and steep turn manoeuvres were conducted, and the pilot was assessed competent in both.
According to the NZ CAA Flight Instructor Guide a steep turn involving an AoB of about 60° is generally approved as a semiaerobatic manoeuvre in most light training aeroplane’s flight manuals.
The pilot did not hold an aerobatic rating and witness statements indicated that the pilot did not like to conduct aerobatics.
Witnesses also stated that he was generally a ‘straight and level’ pilot and would ‘climb to seek smoother air’.
At the time of the accident the pilot had accrued approximately 380 hours fixed-wing experience and approximately 4,300 hours helicopter experience. He held an ATPL-H with an instrument rating and was employed as a helicopter pilot, most recently on a Sikorsky S-76C.
Anecdotal evidence from individuals who knew the pilot, indicated that the pilot liked to fly ‘around the clouds’.
Safety Accident Reports
On the day before the accident flight, the pilot had conducted a local flight in ZK-DVS, to the north-west of Whangarei. During this flight, the pilot climbed the aircraft to an altitude of approximately 6,000ft.
On the accident flight the pilot climbed the aircraft to an altitude of about 4,500ft. On both days cloud layers were reported to be either at or below these altitudes. Comment The report is inconclusive in identifying the underlying cause of this accident, but we do know that an experienced aviator with almost 5,000 hours pilot time, familiar with the aircraft type and more current than many of us, lost control of his aeroplane at height on what was apparently a nice weather flying day.
Although, the combination of a reasonably high performance aeroplane, cloud and startlement would have played a part in his disorientation and failure to take appropriate recovery action.
A good reason, perhaps, to explore the edges of a flight envelope with a qualified instructor as part of some ‘Upset Prevention and Recovery Training’.
Too close for comfort
Fuji FA-200-180 Aero Subaru: G-HAMI Cessna 172R Skyhawk: G-BXGV Near Henley-on-Thames, Oxfordshire Injuries: Nil
Two aircraft had, what was initially believed to be, a near miss while giving air experience flights to disabled children at a multi-aircraft charity event.
It was later discovered that the two aircraft had collided, with one sustaining minor damage, but both aircraft landed safely.
The investigation discovered that one of the accident pilots was asked to present the pilots’ briefing at short notice. The briefing did not include a discussion of how all the participating aircraft would be deconflicted or how they would communicate. It was also reported that not all the pilots that flew were at the briefing.
Both accident pilots stated that their transponders were serviceable, and they were squawking code 7000. However, secondary radar returns were not recorded from either aircraft. It is possible the pilots forgot to select their transponders on. Neither aircraft had any form of EC. Had both transponders been working correctly and one aircraft had EC, the collision might have been avoided.
Recordings of secondary radar might also have given the investigation a better understanding of the circumstances of the collision.
G-BXGV’s pilot was using an electronic navigation aid. Its flight log was made available to the investigation. G-HAMI’s pilot was not using an electronic navigation aid.
The airfield has now installed a programme on a personal computer in its operations room that enables staff to see ADS-B and Modes S equipped aircraft, providing a general overview of the local flying area.
Since this system was installed it has been noted that a ‘surprising number’ of aircraft, which are known to have Mode S transponders do not have them turned on, and that this may be because pilots fear the consequences of being observed infringing the surrounding airspace.
Comment
For every collision there are numerous ‘near misses’, many of which go unreported and probably many more where neither pilot sees the other. While trusting in luck may be OK for some, a midair is not something any of us would want out of choice.
While turning a transponder off may act like the ultimate cloaking device by making you less visible to air traffic, it doesn’t make you any less likely to being hit. Quite the reverse! These pilots were about as lucky as can be, returning themselves and their charges safely back to Earth.
Surviving a midair in which others lose their life would be tough enough, but knowing that one party or the other hadn’t played their part in making themselves visible electronically would be especially difficult to comprehend.
Safety kit
Trouble with wind?
£Free with in-app purchases | Windy.com
This app was found rather by chance, but it has turned out to be a really impressive planning aid, especially for taildragger types operating out of a farm strip where getting ‘actual’ as well as forecast crosswind data is a must.
The app is good for the whole of Europe, offering ‘better quality information than the other weather apps’. It draws on a number of data sources to provide the best coverage possible. Devised originally for Kiters, the read across into aviation is a natural extension. It is updated regularly and has excellent approval ratings. Paying to remove the ads and get a faster update rate may well be worth the investment, although, for now, the basic version seems to work well.
