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Preliminary report into Air India crash released

bbc.co.uk

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Re: Preliminary report into Air India crash released

#131

Post by [deleted] »

lazystar wrote: post #17
decimalenough wrote: post #11

> The aircraft achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42 UTC and immediately thereafter, the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec. The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off. So the fuel supply was cut off intentionally. The swi…

https://ad.easa.europa.eu/ad/NM-18-33 well hold your horses there... from the FAA in their 2019 report linked above: > The Boeing Company (Boeing) received reports from operators of Model 737 airplanes that the fuel control switches were installed with the locking feature disengaged. The fuel control switches (or engine start switches) are installed on the control stand in the flight deck and used by the pilot to sup…

[deleted]

Re: Preliminary report into Air India crash released

#132

Post by aerospace83 »

xenadu02 wrote: post #40
alephnerd wrote: post #14

Earlier quoted context omitted.

> It's difficult to conclude anything other than murder-suicide. Is it possible it could have been an accident or a mistake by one of the pilots? How intention-proofed are engine cutoffs?

It could be defective switch springs, fatigue-induced muscle memory error, or something else. The pilot who did it saying he did not may not have realized what he did. It's pretty common under high workload when you flip the wrong switch or move a control the wrong way to think that you did what you intended to do, not what you actually did. That said Boeing could take a page out of the Garmin GI275. When power is re…

[flagged]

Re: Preliminary report into Air India crash released

#133

Post by lazide »

mallets wrote: post #3

Well, shit. Suicidal? And this can't possibly be all the audio if the other pilot noticed the switch position, I would expect a lot more cussing and struggle. So they didn't notice the switch position? The switch was in the right position but not really? Is this a rarely used switch that one might not look at (or know where to look) during regular use? 10 seconds between OFF and ON.

Dual engine failure on takeoff gives them about as much time to react as if the front passenger grabbed the steering wheel while on a windy mountain road and yanked them off a cliff.

It only takes a few seconds to completely screw everyone, but a bit longer for the consequences to occur.

Re: Preliminary report into Air India crash released

#134

Post by longos »

sillysaurusx wrote: post #50
lazystar wrote: post #17

Earlier quoted context omitted.

https://ad.easa.europa.eu/ad/NM-18-33 well hold your horses there... from the FAA in their 2019 report linked above: > The Boeing Company (Boeing) received reports from operators of Model 737 airplanes that the fuel control switches were installed with the locking feature disengaged. The fuel control switches (or engine start switches) are installed on the control stand in the flight deck and used by the pilot to sup…

https://www.youtube.com/live/SE0BetkXsLg?si=LPss_su3PVTAqGCO Both of these extremely-experienced pilots say that there was near zero chance that the fuel switches were unintentionally moved. They were switched off within one second of each other, which rules out most failure scenarios. If it was an issue with the switches, we also would have seen an air worthiness directive being issued. But they didn’t, because this…

If this is what actually happened it would be the second in recent memory: https://en.wikipedia.org/wiki/Germanwings_Flight_9525.

Re: Preliminary report into Air India crash released

#135

Post by mvdtnz »

cosmicgadget wrote: post #114
snypher wrote: post #66

Earlier quoted context omitted.

I don't understand your question. I have done this myself, am I completely sure?

Did you mean to say you can activate the switches with one hand simultaneously ? That is probably what the above commenter assumed you meant. Since lifting and twisting two switches simultaneously with one hand seems challenging.

It didn't happen simultaneously so this is irrelevant.

Re: Preliminary report into Air India crash released

#136

Post by zarzavat »

rogerrogerr wrote: post #100
codefeenix wrote: post #87

Earlier quoted context omitted.

even though that raising the gear is a up motion and fuelcut off is a down motion?

And fuel cutoff is _two_ down motions? That's the death knell for this theory, imo.

Would anyone be surprised if an accomplished concert pianist played C Bb Bb instead of C E in a piece they had played thousands of times correctly?

The only difference here is that the consequences are death instead of mere head shaking.

Murder needs more proof than just performing the wrong action. Until then we should apply Hanlon's Razor.

Re: Preliminary report into Air India crash released

#137

Post by chmod775 »

russdill wrote: post #124
fsckboy wrote: post #72

it makes sense to me that the pilot who said "I did not do it" actually did do it without realizing it, was supposed to be putting the landing gear up when he committed a muscle memory mistake. it happened around the time the landing gear should be up, and this explanation matches what was said in the cockpit, and the fact that the landing gear wasn't retracted. I think this idea was even floated initially by the you…

There is no possible way to confuse these two actions. There's a reason a wheel is attached to the gear lever.

Sometimes people put cleaning liquid in the fridge.

Given a long enough span of time, every possible fuck up eventually will happen.

Re: Preliminary report into Air India crash released

#138

Post by alvah »

mdavid626 wrote: post #45
lazystar wrote: post #17

Earlier quoted context omitted.

https://ad.easa.europa.eu/ad/NM-18-33 well hold your horses there... from the FAA in their 2019 report linked above: > The Boeing Company (Boeing) received reports from operators of Model 737 airplanes that the fuel control switches were installed with the locking feature disengaged. The fuel control switches (or engine start switches) are installed on the control stand in the flight deck and used by the pilot to sup…

Well, can you move it back, when accidentally activated?

Turbines take a while to spin up again, it's not like start/stop in a car.

Re: Preliminary report into Air India crash released

#139

Post by 747fulloftapes »

fsckboy wrote: post #72

it makes sense to me that the pilot who said "I did not do it" actually did do it without realizing it, was supposed to be putting the landing gear up when he committed a muscle memory mistake. it happened around the time the landing gear should be up, and this explanation matches what was said in the cockpit, and the fact that the landing gear wasn't retracted. I think this idea was even floated initially by the you…

The landing gear lever is rather prominently featured in the 787 in a panel central to the cockpit layout so that either pilot can easily reach it. For decades and across many manufacturers, the landing gear lever has traditionally featured a knob that deliberately resembles an airplane wheel. It's very hard to mistake it for anything else. It's actuated by simply moving it up or down.

The fuel control switches are behind the throttle stalks above the handles to release the engine fire suppression agents. These switches are markedly smaller and have guards on each side protecting them from accidental manipulation. You need to reach behind and twirl your fingers around a bit to reach them. Actuating these switches requires pulling the knob up sufficiently to clear a stop lock before then rotating down. There are two switches that were activated in sequence and in short order.

The pilot monitoring is responsible for raising the gear in response to the pilot flyings' instruction.

I would find it very difficult to believe this was a muscle memory mistake. At the very least, I would want to more evidence supporting such a proposition.

This idea strikes me as even more unlikely than someone shifting their moving vehicle into reverse while intending to activate the window wipers.

Re: Preliminary report into Air India crash released

#140

Post by dcreater »

stefan_ wrote: post #59
dcreater wrote: post #46

Earlier quoted context omitted.

Do you know if the mechanical position of the switch guarantees its electronic state without any possibility for hardware malfunction? If no, then you are claiming a person made one of the most grave acts of inhumanity ever. This sounds to me like an electronics issue - an intermittent, inadvertent state transition likely due to some PCB component malfunction

And then 10s later the switches magically fixed themselves? The likely not electronically connected switches since that would compromise engine redundancy?

intermittent state switching is absolutely a thing in (poorly designed/manufactured/tested/QC'd) electronics
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