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Preliminary report into Air India crash released

(www.bbc.co.uk)
308 points cjr | 7 comments | 11 Jul 25 20:23 UTC | HN request time: 0.001s | source | bottom
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decimalenough ◴[11 Jul 25 21:24 UTC] No.44536914[source]▶
> 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 switches in question are also built so they cannot be triggered accidentally, they need to be unlocked first by pulling them out.

> In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so.

And both pilots deny doing it.

It's difficult to conclude anything other than murder-suicide.

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alephnerd ◴[11 Jul 25 21:30 UTC] No.44536951[source]▶
> 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?

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xenadu02 ◴[11 Jul 25 22:23 UTC] No.44537365[source]▶
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 removed it pops up a "60s to shutdown dialog" that you can cancel. Even if you accidentally press SHUTDOWN it only switches to a 10s countdown with a "CANCEL" button.

They could insert a delay if weight on wheels is off. First engine can shutdown when commanded but second engine goes on 60s delay with EICAS warning countdown. Or just always insert a delay unless the fire handle is pulled.

Still... that has its own set of risks and failure modes to consider.

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aerospace83 ◴[12 Jul 25 00:14 UTC] No.44538111[source]▶
Armchair safety/human factors engineering, gotta love HN.
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1. zahlman ◴[12 Jul 25 00:55 UTC] No.44538342[source]▶
This is a place that puts "Hacker" in the name despite the stigma in the mainstream. Given the intended meaning of the term, I would naturally expect this to be a place where people can speculate and reason from first principles, on the information available to them, in search of some kind of insight, without being shamed for it.

You don't have to like that culture and you also don't have to participate in it. Making a throwaway account to complain about it is not eusocial behaviour, however. If you know something to be wrong with someone else's reasoning, the expected response is to highlight the flaw.

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2. macintux ◴[12 Jul 25 02:53 UTC] No.44538912[source]▶
For me it's mainly about intent/unearned confidence.

If someone is speculating about how such a problem might be solved while not trying to conceal their lack of direct experience, I'm fine with it, but not everyone is.

If someone is accusing the designers of being idiots, with the fix "obvious" because reasons, well, yeah, that's unhelpful.

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3. sdgsdgssdg ◴[12 Jul 25 03:05 UTC] No.44538954[source]▶
(Different user here) Hacker News' "culture" is one of VC tech bros trying to identify monopolies to exploit, presumably so they can be buried with all their money when they die. There's less critical thinking here than you'd find in comments sections for major newspapers.
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4. aerospace83 ◴[12 Jul 25 03:05 UTC] No.44538958[source]▶
> That said Boeing could take a page out of the Garmin GI275

This is not "reasoning from first principles". In fact, I don't think there is any reasoning in the comment.

There is an implication that an obvious solution exists, and then a brief description of said solution.

I am all for speculation and reasoning outside of one's domain, but not low quality commentary like "ugh can't you just do what garmin did".

This is not a throwaway, I'm a lurker, but was compelled to comment. IMHO HN is not the place for "throwaway" ad hominems.

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5. dale_huevo ◴[12 Jul 25 05:30 UTC] No.44539565[source]▶
If Boeing only had the foresight to hire an army of HN webshitters to design the cockpit, this disaster could have been averted.

All the controls would be on a giant touchscreen, with the fuel switches behind a hamburger button (that responded poorly and erratically to touch gestures). Even a suicidal pilot wouldn't be able to activate it.

6. michaelmrose ◴[12 Jul 25 05:58 UTC] No.44539691[source]▶
I don't think most think they know better but it's frankly fun to speculate and this is a casual space rather than the serious bodies tasked with actually chewing over this problem in earnest.
7. Mawr ◴[12 Jul 25 08:29 UTC] No.44540314[source]▶
> This is not "reasoning from first principles".

It literally is. Accidental/malicious activation can be catastrophic, therefore it must be guarded against. First principles.

The shutoff timer screen given as an example is a valid way of accomplishing it. Not directly applicable to aircraft, but that's not the point.

> "ugh can't you just do what garmin did"

That's your dishonest interpretation of a post that offers reasonable, relevant suggestions. Don't tell me I need to start quoting that post to prove so. It's right there.