By a strange coincidence, two sad events happened in the first six months of 1972, both of them on Sunday afternoons. Here are my thoughts on the second incident: the crash of BEA548, sometimes known as the Trident Disaster or the Staines Air Disaster. My thoughts on the other event (Bloody Sunday) can be found under ‘Irish History’.
UPDATE – February 2014
The latest series of ‘Mayday’ aka ‘Air Crash Investigation’ has finally tackled BEA548!
The programme needed to cover a lot of ground and largely succeeded, although some issues were not covered well (if at all). The computer graphics and dramatisation were – of course – chilling and brought a new level of realism to the story.
I thought the programme was careful not to state that Captain Key suffered a heart attack, only a dangerous and uncomfortable heart condition that had worsened before the crash. However, the main question as to who moved the droop lever was quietly dropped in favour of a general conclusion based around what the crash did for aviation safety (which was substantial).
BEA548 – Staines, London, 18th June 1972
What makes a fully operational passenger jet fall out of the sky? Here is an attempt to answer the enduring mystery of BEA548:
Overview of the event
BEA548 was a scheduled British European Airways (BEA) passenger flight from Heathrow to Brussels. The aircraft was a Hawker Siddeley Trident, a popular short-haul passenger aircraft. The weather was overcast and windy, but not particularly hazardous.
The plane crashed at 1611 that afternoon, 3 minutes after taking off from London Heathrow, killing all 118 passengers and crew. Two people, a man and a young girl, were found alive but sadly died minutes later.
A crucial issue was uncovered by the initial investigation team just hours later (and informally confirmed by BEA pilots who were at the scene of the crash): why were the high lift devices, the so-called ‘droops’, not activated on the crashed jet? Instead of being extended, the droops and flaps were retracted into the leading and trailing edges of the wings. The wings were flat at a time in the flight when they should not have been. This unexplained change of aircraft configuration undoubtedly caused the Trident to enter a deep stall and crash.
The exact reason for the premature droop retraction has remained a mystery for many years simply because at the time UK passenger aircraft did not have ‘black box’ voice recorders in the cockpit (although this crash was instrumental in getting them fitted to UK airliners). Therefore, the interplay between the four people on the flight deck can never be known. The only information available came from a Flight Data Recorder which explained how the aircraft flew (speed, heading, altitude etc.) and which controls were being operated.
The human factors
A crucial issue in the crash was an airline pilots strike that was taking place at the time. The strike had caused deep divisions amongst BEA pilots and the ill-feeling led to arguments and occasionally grafitti directed towards senior pilots.
The pilot of BEA548 was Stanley Key, an experienced pilot and WWII veteran. He was known to be a pilot who kept strictly to the rules and did not appreciate slackness from his crew. He was no doubt respected – and feared – by younger pilots, especially in an age when seniority often seemed all-powerful and unquestioned (especially if you had served in the War, still barely less than 25 years before).
Key’s co-pilot for this flight was an inexperienced trainee pilot, 22 year old Jeremy Keighley. He was co-pilot due to a policy BEA had put in place to alleviate staffing issues caused by the strike. Although inexperienced on Tridents, he had flown enough flights on the aircraft to be competent, although he had never flown with Captian Key before and it is possible that he was somewhat concerned about Key’s reputation. This would have been made worse by the fact that he almost certainly saw Captain Key explode with rage in the BEA crewroom about 2 hours before the flight when Key was discussing the strike with a fellow BEA pilot. Although the dispute with a fellow officer was quickly resolved, and Key apologised, it may have left the impression that Key was volatile and not to be queried.
Monitoring pilot for this flight was Simon Ticehurst, a more experienced Trident pilot, but still young at 24 years old. Sitting behind the front seats, his job was to monitor various instruments and closely watch the actions of pilot and co-pilot to ensure safety. With hindsight, Ticehurst’s role was a crucial one and he appears to bear a significant amount of responsibility for the ensuing events.
Unusually, there was a 4th pilot aboard that afternoon. Captain John Collins was an experienced BEA pilot who, with his crew, was on his way to collect another aircraft from Brussels. Although not currently a Trident pilot, he had many years experience on the aircraft and appears to have been a friend of Stanley Key. He occupied the jump seat, near Ticehurst, at the rear of the cockpit. Usually this seat was empty, but because of the strike, the plane was full and therefore seats for Collins and his crew were scarce. Therefore, Key invited him into the cockpit. The official accident report is guarded about Captain Collins but does suggest that he may have been distracting the crew from their duties (some say telling jokes). His presence is another example of the fateful combination of factors that leads to an accident, although no one factor on its own seems significant, or even dangerous. (It is worth noting at this point that some sources believe that due to the location of his headphones in the wreckage, John Collins may well have been assisting in correcting the droops error seconds before the crash.) Whatever happened, Captain Collins would not have been expected to play any part in the flight under normal circumstances.
At 1608 BEA548 was cleared for take-off, following a short delay on the end of the runway, possibly due to a minor technical error. The plane climbed normally and began to bank left towards the Epsom radio beacon. Records show that Key liked to engage autopilot early and, although this was not unsafe, it was not normal operating procedure. On this flight, the plane’s speed was a little slow during the take-off climb, leaving no margin for error should something go wrong. It is not clear why this should have happened.
Other activities on board the flight appear to have been normal, with Key making two transmissions to air traffic control (the second message being somewhat non-standard in its brevity).
114 seconds into the flight, and at 1770 feet and 162 knots (now considerably slower than expected) the high lift devices lever was moved, moving the droops inward towards the leading edge of the wing, the droops having been extended for take-off. This operation was entirely non-standard and is inexplicable. Without correcting this error, the Trident’s chances of survival were now slim as the devices that gave it the necessary lift to climb were now useless. Note: this action would have resulted in a ‘Droops out of position’ warning that was visible to all three pilots.
Possible corrective action
What could – or should – the crew have done at this point?
- The droops should have been extended immediately. This would have prevented the deep-stall condition.
- If the droops could not been extended, the aircraft should have had its nose pointed downwards and engine power increased to significantly raise the airspeed and prevent a stall.
Tragically, neither of these actions were carried out. Instead, Captain Key ignored the stall warning devices (called the stick shaker and the stick pusher) and soon afterwards disconnected them. He continued attempting to climb at the designated rate, all the while losing airspeed and entering the deep-stall condition. Once the plane had deep-stalled, with the nose pointing skyward but with little forward motion, only rapid downwards motion, nothing but a miracle could have saved the aircraft. In fact, Trident test pilots had perished several years before in a similar deep-stall, meaning that airline pilots, with their far less extensive range of flying experience, were extremely unlikely to be able to recover the plane.
At 1611, BEA548 crashed into a field near the Crooked Billet roundabout in Staines, having missed a reservoir and a busy main road. All on board were killed, most of them instantly due to the high impact landing. The plane broke into sections but was not consumed by a fire, despite there being a lot of aviation fuel still on board.
Initially, the crash went virtually undetected, but the emergency services put in a large clear-up effort, working late into the summer evening to recover bodies. At the time it was Britain’s worst air crash.
Within hours, accident investigators knew that the aircraft had deep-stalled. They also suspected that the aircraft was in good condition without any technical failures and that human error was the cause of the crash. Time would prove them absolutely correct in these assumptions.
What could have happened to Captain Key?
The subsequent inquiry found that Captain Key was not as healthy as he was thought to be. Medical science at the time was not adept at spotting heart conditions and his autopsy found he was suffering from serious heart disease, despite getting a clean bill of health on his regular checkups. The inquiry heard that there was a haemorrage in his heart at some point in his final two hours. It could only be speculated what effect it would have had on this most experienced of pilots, but it seems likely that he was suffering discomfort during take-off. This could explain the speed error and the brief message to air traffic control. (It was possible that the haemorrage was a result of the argument in the crew room, which was said to be excessively violent in tone.)
It is therefore likely that it was Captain Key who moved the droop retraction lever, possibly in some form of pain and confusion. He may have thought he was operating the flaps whose lever was next to the droops lever and looked similar, although they had just been raised.
It is then possible that the confused captain was further perplexed by the stall warnings (the system was known to trigger false alarms and was often ignored) and over-rode them. The stick pusher would actually have moved the aircraft’s nose down automatically, something he would have seen as incorrect and hampering the normal operation of his flight. Therefore, thinking that the aircraft was in the correct configuration and flying at the appropriate speed, the captain viewed the stall warnings as unnecessary intrusions that were hampering the flight – and attempted to carry on without further obstructions.
Some speculate that the heart condition was so severe that Captain Key may have died at the controls before impact. This would explain the extraordinary turn of events.
(It is worth pointing out that the investigation uncovered one possible incident of a Trident droop retraction lever moving without human assistance, but it was never proven to have actually happened. I will discount this particular theory.)
What were the other three pilots doing?
We have already mentioned that Captain Collins was only an observer on the flight deck and therefore he was not responsible for the flight.
It is possible to imagine Keighley being excessively preoccupied with following procedure and making sure that Captain Key was happy with his performance. As a trainee, it is not unreasonable to expect that he would still be working fairly slowly as he operated the throttles etc. and therefore may have missed the significant loss of airspeed. It was later discovered that Keighley was slow to react to accident scenarios in training and this must surely have meant that when disaster was staring him in the face, he would have felt overwhelmed by the situation. It is interesting to note that the accident report is very forgiving here: This was an earnest young man who was determined to do his best.
Ticehurst’s apparent lack of reaction to unfolding events is not clear. As monitoring pilot, he didn’t have anything else to do other than watch Key and Keighley. He would have been looking closely at the speed and altitude and therefore it is a mystery as to why he did not raise the alarm sooner. Therefore, was he distracted by Captain Collins?
Was Captain Collins telling jokes? This seems unlikley for several reasons:
- Both Ticehurst and Keighley had written down flight clearance to 6000 feet in their logbooks, so we can assume they were paying a decent amount of attention to the flight.
- John Collins was an experienced pilot and would surely not have been unprofessional in this way.
- If he and Key had known each other for some time, and Collins had been entertaining the crew with humour, Key’s relationship with Collins would have been robust enough for Key to politely tell him to stop until they had reached an appropriate time, such as crusing altitude. (It is understandable that the junior pilots would not perhaps have felt able to do this.)
- If Key did feel unwell, he would not likely have appreciated the extra distraction and noise in the cockpit – another reason to tell Collins to keep quiet.
However, as Christopher Bartlett points out in ‘Air Crashes and Miracle Landings’, Captain Collins was found in the wreckage holding a can of standard issue air freshener, which would have been used on his freighter flights. This is an odd detail, and it may have no meaning whatsoever. Bartlett surely speculates too far by suggesting that Collins may have been standing up using the air freshener and fell across Keighley, blocking his view.
Why then did Ticehurst not make it abundantly clear what was happening when the stick shaker and stick pushers operated? Even if Ticehurst did not have his mind on the job before this moment, this series of alarms would have focussed his mind completely. Why was he not able to tell the pilots that this alarm was, indeed, genuine and that the aircraft was in danger? This, to me, is the heart of the mystery. The monitoring pilot could have pointed out exactly what the problem was and got the pilots to make the appropriate corrections. Ticehurst had over 750 hours on Tridents and should have known exactly what was wrong.
Therefore, Ticehurst to me is a crucial player in this disaster. Most speculative scenarios surrounding the disaster should not be able to happen with a monitoring pilot present. For example:
Some have speculated that a nervous Keighley misunderstood a command from an impatient Key and retracted the droops. Even if this did happen, and Key was becoming disorientated, why would Ticehurst not have noticed this crucial and dangerous error and got it corrected? Is it possible that Ticehurst was also nervous about flying with Key and therefore didn’t want to question a senior pilot (in front of another senior pilot)? This also seems unlikely:
- Ticehurst had 750 hours experience on Tridents and was not a trainee. His voice would have carried significant professional authority.
- If Ticehurst had seen the droops prematurely retracted he would have known that a crash was becoming likely and this would have surely overcome any possible inhibitions he may have had.
- Ticehurst is thought to have agreed with Key over the pilots strike and, as an established albeit younger pilot, would not have been frightened about Key’s seniority.
The final analysis
Having examined the four people on the flight deck as the disaster unfolded, it seems likely that the situation must have been caused by something so unusual that the three crew members, plus Captain Collins, were totally confounded by the situation they faced.
I have mentioned Ticehurst several times and it is hard to understand why this experienced monitoring pilot did not prevent the tragedy. It is fair to assume that he was massively distracted soon after completing his flight log entry. It is possible that, prior to this, he may have overlooked or chosen to ignore the overall speed of the flight, which was becoming less and less within the bounds of operating procedure, but it simply is not possible that he could have misunderstood the stick shaker and pusher. He would surely have instantly checked the airspeed upon seeing such an alarm, worked out that the alarms were genuine and then tried to find the cause. The ‘Droops out of position’ warning would have been the clue he needed for an effective course of action.
On mitigating circumstance is that the chain of events did happen extremely quickly and this should be borne in mind. Not all the reactions and actions of the crew would have been perfect, but the main focus would have been on keeping the aircraft flying and finding out why this was not possible. It is thought that the crew had about 15 seconds from droop retraction to deep stall to find out what was wrong and make corrections.
In the final analysis, we need an ususual event to explain the mystery of BEA548. The only factor which can explain this is that of Captain Key’s heart condition. It is logical to conclude that, despite mixed views from the heart experts at the enquiry, that he stopped flying the aircraft correctly and became disorientated. In so doing, he diverted the attention of the other crew members, and particularly Ticehurst who would have had more freedom of movement and a less crucial hands-on flying role.
This then explains why the causes of the stall went uncorrected: the crew saw that the Captain was in serious trouble and were attending to him in some way. I do not know if Ticeburst was strapped in during impact, but it is possible that he left his seat and attempted to rouse Captain Key from possible unconsciousness, or possibly wrest his hands from the controls if he was beginning to fly in such a way as to cause immediate danger to the aircraft (and it seems like this was happening as he attempted to continue climbing with the droops retracted and a critically low airspeed).
It is then possible that Captain Collins left his seat and sensing the immenient danger and the fact that an inexperienced and possibly panicking pilot was in control of the aircraft, went over to offer assistance to Keighley. This would explain why his headphones were found in Keighley’s footwell. However, with so little time and no active involvement in the flight so far, Collins could not identify the problem quickly enough. There is no evidence that the droops were beginning to extend on impact, so it seems that the droops went uncorrected.
Another factor to consider, and one that makes the above scenario less likely, is that room in the cockpit would have been very tight and could Ticehurst and Collins actually have leaned over one another in this way? Did Collins go to Key and Ticehurst to Keighley? There is a spatial sense to this hypothesis and also a human one: the older men, and friends, helped one another and the younger men helped one another. If so, how did Collins’ headphones end up where they did?
For all the speculations and mystery surrounding this event, we must always remember that 118 people, some of them women and children, died that Sunday afternoon. Whatever did happen on the flight deck, we must be aware that the crew were human beings, people capable of great acts of heroism, and also people who, like all of us, were prone to mistakes.
Finally, we should remember the airline pilots strike. It undoubtedly had an effect on BEA aircrew. There was a crucial vote planned for the next day, which was the cause of much discussion and tension. The strike also meant that BEA were having to make compromises on pilot positions in the cockpit. Jeremy Keighley was not ideally suited to the role of a co-pilot at this stage in his career. Had Simon Ticehurst been in that seat, with Keighley monitoring, perhaps things would have been different.
If there had been no strike, perhaps Stanley Key would not have argued with another officer hours before he was due to fly. His heart condition could have remained dormat until his next medical (when perhaps it would have been spotted, at last) and the flight to Brussels would have proceeded without incident, like so many Trident flights before and after it.
This page is dedicated to the 118 people who perished on board BEA548 ‘Papa India’ on 18th June 1972.
Official accident report available here: http://www.aaib.gov.uk/publications/formal_reports/4_1973__g_arpi.cfm