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Preliminary report into Air India crash released

bbc.co.uk

121–130 of 924 posts

Re: Preliminary report into Air India crash released

#121

Earlier quoted context omitted.

Someone took their hand, pulled one spring-loaded switch into the off position, and then did it the other switch moments later. Is there any way that could be accidental? If there was no mechanical failure, the only remaining possibility is deliberate action. And if it was mechanical failure, we’d see an emergency air worthiness directive being issued, which we haven’t.

People do things bizarre, inexplicable things all the time. It's called a brain fart... the human brain is complicated, sometimes wires just get crossed. Honestly I think the chances are good that you're right, but the way you're presenting it as absolutely certain strikes me as overconfident, borderline arrogant. Also, what's with the whole "staking your reputation" thing? What reputation? Are you some kind of famou…

Well, you do now. :)

It’s mostly a very public "If I’m wrong, I won’t ever do this again." I’ve been writing informative HN comments since 2008 on various accounts. It’s a big deal to me not to spread misinformation or be mistaken in a situation like this.

The victims also deserve to be acknowledged. At this point the overwhelming body of evidence points to a deliberate act. Pilots are trained never to touch the fuel switches in flight, and (I believe) there is a verbal confirmation required before toggling. This captain had over 8,000 hours.

The reason I’m so confident is because I trust the system. It’s designed so that if either of the two pilots do anything, they verbally call it out, e.g. "gear up." A callout like that followed by fuel switch cutoff would indicate it was accidental. But as far as I know, there was no callout.

The pilot flying is also the one who asks for gear up and such. It’s the job do the pilot monitoring to perform those actions.

Suppose it was accidental. That would mean the pilot flying was fiddling with switches instead of flying; that’s against SOP. Or it would mean the pilot monitoring was performing uncommanded actions, which is also against SOP. It’s not something that happens on a whim. Both are contradictions, hence, no accident.

As for being overconfident or arrogant, what matters to me is accuracy, and passing along that accuracy. No one seemed to be willing to publicly call this a malicious action, so I did. If I’m wrong, you can be sure I’ll feel terrible for weeks, post an apology in the thread that shows I was wrong, and then bow out in disgrace, never to cover news again.

People here did the same thing when the common belief was that there was a non-zero chance of nuclear war. I was one of the few voices in that thread saying absolutely not, stop stressing yourself out for no reason.

I’m simply one voice of many. As always, it’s up to the reader to decide what to believe.

Re: Preliminary report into Air India crash released

#122

> 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…

These switches are operated at startup and shutdown. So pretty much daily. By pilots and likely maintenance crews. Such a defect with not to unnoticed for long

Re: Preliminary report into Air India crash released

#123

> 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…

> 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. > As per the EAFR, the Engine 1 fuel cutoff switch tr…

> Boeing's probably gonna have a big sigh of relief over this one.

The 787 is 15 years old, and this particular plane was 10 years old. It always seemed unlikely to be a major, new issue. My money was actually on maintenance.

Re: Preliminary report into Air India crash released

#124
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.

Re: Preliminary report into Air India crash released

#125

Why can the pilot shut off the fuel during takeoff?

Fire, probably. But also, how complicated would you make the system if you needed to prevent certain switches from working during certain times of flight? At some point... we're all just in the hands of the people in the cockpit.

Re: Preliminary report into Air India crash released

#126
post #30

Earlier quoted context omitted.

The only affected models were 737s with the 766AT613-3D fuel control switch. The bulletin recommended that other models be inspected and any defects reported. It's unclear if any 787s were discovered to have the issue. Also the preliminary report mentions that the switches were replaced in 2019 and 2023, after the 2018 bulletin.

still, it at least shows that there's been issues with the locking mechanism in the past. inadvertently bumping something that was assumed to be locked is a simpler theory; i find it hard to believe that a murder suicider would take this route, when the china nosedive option is easier, faster, and has a higher chance of success.

The preliminary report says the switches were triggered a second apart, so it would have to have been faulty switches and two inadvertent bumps. That seems unlikely to me.

Re: Preliminary report into Air India crash released

#128

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.

i have several passwords i type all the time. sometimes i get them confused and type the wrong one to the wrong prompt. i type them by muscle memory, but i also think about them while typing and i think thoughts like "time to reach up and to the left on the keyboard for this password". I couldn't tell you the letter i'm trying to type, i just know to do that.

not all my passwords are up and to the left, some are down and to the right, but when i type the wrong one into the wrong place, i type it accurately, i'm just not supposed to be typing it.

"time to do that thing i've practiced, reach to the left". shuts two engines off by muscle memory.

Re: Preliminary report into Air India crash released

#129
post #92

Earlier quoted context omitted.

Cutting fuel just after takeoff leaves almost zero time for the other pilot to recover.

It's interesting to try to imagine a device that would prevent that, without causing more issues. My preliminary idea is a "fuel bladder" for take-off that inflates with enough fuel to get the plane to a recoverable altitude, maybe a few thousand feet?

I think engine fires are still more common than suicidal pilots and inadvertant fuel shutoff activations.

Re: Preliminary report into Air India crash released

#130
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…

One of the nice things about finally having the preliminary report is I get to stop hearing all of the same assumptions/theories/YouTuber said/"a guy I know got a leaked report"/etc in water cooler talk at work because the preliminary report solidly disproved all of them so far. If anyone even had and stuck with an idea matching this report it wouldn't have stood out in the conversations anyways.

The collection of comments on this post remind me it'll just be a brand new set of random guesses until the final report is released. Or worse - the final report reaches no further conclusions and it just has to fade out of interest naturally over time.

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