Having done due diligence viz. read preliminary crash report, the ‘fuel cut-off’ safety bulletin and Honeywell’s glossy brochure I can confidently state we’re no nearer the truth.
But of most concern to the ‘fliterati’ of which I’m a founding member was the time it took to shed light on an accident involving a near-total loss of hull and life, yet led to no fleet-wide safety recommendation in the aftermath. This can only mean that those in the know were in the know very soon after the event, and possibly within minutes.
For satellite communications routinely relay maintenance data to manufacturers of engines and airframes, including failure analyses. And of these, your double-engine stoppage is given top billing. I’m no expert, but am throwing that ADS-B in there as a possibility?
Back to suicide though (before I set the ‘mise en scene’) ~ of which there are some half-dozen recorded cases and more prior involving life insurance. For there is likely no better time nor way of doing this than stopping both engines on take-off at time ending :42 and just three seconds after becoming airborne. Having been an airline pilot too long, I don’t view it as something too tasteless to ask, or at least not given the tastelessness of two hundred fatalities.
And back to review the only eye-witness account which featured only an alteration to the cabin lighting that we attributed to engine generators dropping off line and the subsequent switching… and the BANG, which remains unattributed?
The latter had me thinking, but firstly let's re-cap those engine fuel cut-off switches. They are and always have been the means of starting or stopping jet turbines. At start a motor run on compressed air cranks the engine to a 'max-motoring' RPM at around 20%, when the fuel is introduced by manually shifting a lever (as was) from CUT-OFF to RUN; and to stop the engines at the gate, simply reverse this motion in quick succession.
I say switches, because modern airliners with computer-controlled jet-engines use these instead of mechanical controls to provide fuel to start, re-light or stop jet engines when otherwise pilots would have manually operated a lever. If you're still with me, give yourself an airline transport licence.
Now on the ground at the get-go and gate, the switches are operated by PF or pilot flying, which in the case of the ‘accident’ was the co-pilot. Until recently aviation on the Indian sub-co was administered by old farts, and the sensible way to circumvent this was to obtain a licence fraudulently. It meant though that for a long time only the captain started the engines and taxied to the runway, but under pressure from manufacturers this is rarely any longer the case... although some aircraft out there still only sport a single 'steering wheel' or tiller for the captain.
This though is the only time ~ and on the ground ~ when fuel-cut offs are operated unguarded by either pilot or indeed the design of the mechanical switch. Airborne neither switch is manipulated without duel consent, which is natural given you may be about to shut down the one engine you have left. To stop inadvertent selection, what once were levers but are now switches have to be lifted out of a 'detent' or an internal catch before they can be raised or lowered: the switch in the picture is the type on the 787, less a plastic knob-end (of the kind on switches and not seats).
So far so bad, and so as to the safety bulletin regarding these switches, SAIBS are issued by the thousand. You know when you’re so bored you read the safety card? Well pilots do that with SAIBs. And flying being (like Parkrun) a competitive sport tho' we pretend it is not, there's always the pilot who says 'Let me stop you there, Kev, because I do believe that’s the Honeywell 4TL837-TD you’re referring to and not the TC' whilst adding another tick to his book.
But the SAIB regarding the switch basically says that the guard may be missing if you try it, and if you do so and it is missing then it needs replacing soonest. Such SAIBs however are divided among a to-do list, and I suspect this one to have been given top billing since the crash. Previous though it was a ‘nice to do’ and thus kicked down the road, being something of a pain in everyone's ass, like the curtain-pole you're not fixing until prior the first viewing.
Yet engines do not turn themselves off, because we’re not driving Teslas, so what else might cause this in the circs: whether external, internal or human?
Regards the first, despite aviation analysing anything you could think of forensically ~ and thus being aped for safety purposes by every other organisation ~ one thing I can call to mind that happened like clockwork (yet merely viral among colleagues) was a bang on take-off at Belfast, where 737s used the same runway on the same shuttle to London incessantly and ALWAYS took off at the same point. Thereabouts on the runway there was a depression resulting from wear-and-tear that crew would experience as a marked BANG from the undercarriage much like the government does to us with its pothole program.
On one occasion flying with the good ship Evans ~ who went on to senior roles at Easyjet ~ we heard such a report on departing LHR and left the gear down to return by way of a precaution. (In those days the 737 had a spy-glass under the carpet in the cabin where you could inspect the landing gear… passengers would ask me why they had to move and I'd tell them it was so that we didn't die.
Could this have accounted for both the BANG the survivor heard, along with shock displacement of much-too-easy-to-move cut-off switches? No, but one Poirot would throw into the mix as he leant on the mantelpiece. The prelim confirms it, too, as it states cut-offs were moved three seconds after take-off and a second apart: much, as Poirot points out, as they may were they used during a routine shutdown.
As yet, the CVR only reveals that one or other pilot asked the other why the other just did that ~ as you may, should you be dying ~ but the great and good say they have yet to analyse whose voice is whose. One belongs to a fifty-six year old and the other to a thirty-two, so I guess it’s not rocket-science; the US sufficiently is litigious however to defer this even were it Darth Vader chatting with Minnie Mouse.
So listen up you at the back, because though I’m as bored with this as you are, there will still be questions.
During take-off it remains routine ~ I cannot be bothered checking, it being 2025 ~ for captains to rest their hands on the thrust-levers, so as to be able to call STOP in the event of emergency prior take-off, and pull them back soonest. (In a concession I recall British Airways let PF leave a hand there, the captain's resting gently on top: leading to at least one same-sex marriage at the airline.)
Assuming the captain though to be charged with the thrust levers, the PF or co-pilot is wholly concentrated on keeping several hundred tons of aircraft going straight, as marked by a white dashed line from which ‘cats-eye’ style embedded lighting is off-set. (Eventually during this phase I could tell when the twin tyres of the nose-wheel straddled these lights with nairy a drift left or right, given the knocking that ensued otherwise. I really was that good, at least before that crash that took it all away).
Then at the call of V1 or go-speed the captain will stop covering the thrust-levers to avoid inadvertent mistakes, while PF will pitch toward V2, blue line or safety speed. This is a target for best rate of climb should one engine drop out, beside a few knots for granny. At such time PF will move to cover the thrust-levers, which after lift-off have anyhow come under the command of the auto-thrust: this is because said A/T does not have the last word on reducing thrust in the event of fire or failure, which is left to pilot discretion and a checklist.
So during the take-off the co-pilot has a clear albeit peripheral view of what is going on. Trucks nowadays use cameras with a comprehensive internal and external view and despite it being long a recommendation among aviation authorities it has yet to be implemented, resisted by all concerned and not least aircrew, who may (it has been known) be seeing tits got out up-front.
But in our case under review one or other pilot asks the other why, three seconds after lift-off and prior retraction of the landing gear, the other moved said switches… and we don't know who did what in the absence of video or more info from the CVR or cockpit voice recorder. In response and only seconds later, each switch was set back to RUN in turn, enabling the FADEC (computer controlling the engines) to try for a relight of the sort that is easiest whilst engines are still spinning at speed.
As a consequence one re-light was proving successful ~ likely the later to have been shut down ~ whilst the other proved more problematic. It is intriguing to think that even at this late stage had the landing gear been raised to reduce drag, the aircraft may yet have climbed away. But then life's not always like that.
Reasons though for cutting off fuel switches, by way of re-cap, include (a) life not as good as it could be, and this being a way to end it (b) a mental moment not unlike climbing stairs and wondering why (c) muscle memory that does something that it shouldn’t.
These have all sorts of names amongst what pilots call psycho-babble, but don’t in the UK any more for fear of imprisonment: sequence errors, errors of omission and commission, perception errors and unwritten ‘fuck-you’ errors like landing heavily or taxying extra slowly to aggravate a management who likely deserve it.
What is most telling though is why in this case and when challenged, he who turned the fuel off turned it back on again? Would you do that had you moved the switches OFF on purpose?
Well in a reflex that I’ll call ‘naughty corner syndrome’ and which I hope appears in textbooks, it may be a caught-in-the-act response or simply a change of mind or a reversal of an inadvertent action whilst the situation might still be recovered. For the only other part of the CVR transcript we have relates to a MAYDAY call in which they forgot to identify the aircraft with an emergency and a suggestion to air traffic control that there was simply no (or insufficient) power.
So we’ve considered external (or pot-hole) besides human reasons for de-selection, but what of internal? Moving one wrong switch or any when none require it is known as ‘finger trouble’ among pilots, but inadvertent switch selection might also be known as ‘flying object’ trouble should anything removable collide with switches.
Fighter jet cockpits are as sterile as operating theatres and should you drop even a pin, have to be taken apart until it is found and removed. Airline flight-decks are a smorgasbord of past meals, a detritus of lost pies and bottles that has worked its way to the deck below and sits on a tarp that protects the electricals: remove it and its contents and you’ve a ready-made picnic.
(Landing once in Sweden I registered something like a large rodent pass by my feet only to disappear thus: a two-litre bottle of water so large and unnecessary as to need reporting to our equally large and unnecessary management.)
'Could then an object have knocked both switches down inadvertently, mon amis?
'Non, and not unless it did so in a sequence one second apart!’ exclaims Poirot.
For here’s the rub: despite switches being selected OFF at time :42 and one pilot asking the other why he had done this, the other said that he had not.
I'm going to leave you with Columbo now in his crumpled mackintosh as he gets to the door, ruffles his hair, holds his hand to his forehead and turns back to say:
'There’s just one thing I can’t figure ~ which I mentioned to Mrs Columbo ~ just how it is that one pilot knows the other has cut the switches anyhow? As a young PF here I'm fixated on those instruments at a critical phase yet able to link dual engine failure to something that never happens and query it for the benefit of the tape?'
'I’m gonna need a coffee here because I’m wondering if the captain drops his hands from the thrust-levers via those switches, selects them off and and then asks pilot flying why HE just cut the fuel off... that same pilot who says that he hasn’t?'.
For Agatha Christie, mysteries were not something to be considered super-human but invariably something altogether less so. It may yet have been the aircraft and not the crew, but a reason to demur in the case of aircraft accidents is that should the cause prove embarrassing, it no longer matters as we're already onto the next.
Like Gregory House MD, I'm just the one penning stuff on the whiteboard.
