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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

#321

Post by dyauspitr »

WalterBright wrote: post #253
dyauspitr wrote: post #162

Earlier quoted context omitted.

If you shut off the engines a couple of dozen meters above ground shouldn’t every alarm be blaring or there should be some sort of additional lever you have to pull way out of the way to enable shutting off the engine that close to the ground.

Consider a case where the engine starts to violently vibrate. This can tear the structure apart. Delaying shutting off the engine can be catastrophic. It's very hard to solve one problem without creating another. At some point, you just gotta trust the pilot.

Would it matter in this case since you would crash either ways. I’m talking about protection in a very specific situation where you make it harder to shut off both engines when you’re very close to the ground.

Re: Preliminary report into Air India crash released

#322

Post by dale_huevo »

sdgsdgssdg wrote: post #249
zahlman wrote: post #159

Earlier quoted context omitted.

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…

(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.

[flagged]

Re: Preliminary report into Air India crash released

#323

Post by emmelaich »

sgentle wrote: post #215
dboreham wrote: post #171

Earlier quoted context omitted.

I can't put my car into reverse gear while driving down the freeway.

Sure, but you can open the door, pull the handbrake, or turn the wheel so hard you lose control of the vehicle. These are all similarly preventable, but maybe not worth the risk of being unable to open the door, brake or steer if the safety mechanism fails closed, or if your situation is outside the foresight of its designer. Also, you don't need multiple certifications and 1500 hours of experience to drive a car.

On a Tesla (and presumably other cars) opening the door engages Park.

There's no handbrake to pull, and turning the wheel so hard to lose control is next to impossible. Maybe on an oily wet or loose surface.

Re: Preliminary report into Air India crash released

#324

Post by coolspot »

card_zero wrote: post #317
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…

Cutting the engines within seconds of leaving the ground doesn't fit suicide very well. I'd expect something more like flying into the side of a mountain or heading really far out into the Indian ocean until you vanish from radar and cause a big mystery. For instance, you might deliberately kill yourself by driving your car really fast into something solid, but you probably wouldn't try to do that while backing out o…

I think it is opposite. Flying into a mountain & etc would require one pilot to somehow incapacitate another pilot. Cutting fuel off, if done on takeoff, is not recoverable (engines can’t relight and spin up quickly enough).

Re: Preliminary report into Air India crash released

#326

Post by burnt-resistor »

sugarpimpdorsey wrote: post #294
burnt-resistor wrote: post #275

Earlier quoted context omitted.

> It's difficult to conclude anything other than murder-suicide. You're leaping into the minds of others and drawing conclusions of their intent. One of them moved the levers. It could've been an unplanned reaction, a terrible mistake, or it could've been intentional. We may never know the intention even with a comprehensive and complete investigation. To claim otherwise is arrogance.

> One of them moved the levers. It could've been an unplanned reaction, a terrible mistake, or it could've been intentional. Fuel levers are designed to only be moved deliberately; they cannot be mistaken for something else by a professional pilot. It's literally their job to know where these buttons are, what they do, and when to (not) push them. It's not arrogance to assume the most likely conclusion is true, despi…

> cannot be mistaken for something else

Assumption. Big ass assumption.

Pilot are trained until actions are instinctual and certain memory items are almost unconscious. But pilots are still people and people are fallible and make mistakes, and sometimes act unreasonably. Intent cannot be determined without clear evidence or statements because that's now how thoughts locked away in people's minds work.

> It's not arrogance to assume the most likely conclusion is true

You don't know this. This is beyond the capability to know and is therefore pure speculation. That is the definition of arrogance.

Re: Preliminary report into Air India crash released

#327

Post by michaelmrose »

Epa095 wrote: post #211
userbinator wrote: post #158

Earlier quoted context omitted.

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 Or more precisely, the signals which come from them were found to behave as such. Without any audible record of turning the switches off, I wouldn't blame the pilots without first checking the wiring and switches themselves for faults. This reminds me of the g…

But from the audio recording it seems like one pilot is noticing them bering in the CUTOFF position, and asking why (and moving it back). If the switch was actually in RUN, but some other issue caused the signal to be sendt, the pilot would see it beeing in the RUN position, not CUTTOF.

Are they looking at the physical switch or data about the state of the engine displayed in some other fashion?

Re: Preliminary report into Air India crash released

#328

Post by ExoticPearTree »

arp242 wrote: post #201
snypher wrote: post #33

Earlier quoted context omitted.

There's a good photo of them here; https://theaircurrent.com/aviation-safety/ai171-investigatio... You can do them both with one hand.

Is there just one set of switches? Or do both pilots have their own set?

Only one set.

Re: Preliminary report into Air India crash released

#329

Post by whatevaa »

moralestapia wrote: post #318
alphabettsy wrote: post #58

Earlier quoted context omitted.

that doesn’t tell us they were fresh. Only that they hadn’t flown. They could’ve slept 0 hours before or any number of things.

Sure, and aliens could also be involved. However, the only relevant evidence that exists suggests they had enough rest. You don't build verdicts on suppositions, you build them on proven facts. This does not guarantee you will reach the truth, but it's miles better than admitting every baseless hypothesis that comes up.

This is preliminary report. They will look deeper into this.

Don't sentence people on unfinished investigations. This is why most trials are not public, because of people like you.

Re: Preliminary report into Air India crash released

#330

Post by OneMorePerson »

p1mrx wrote: post #217
pixl97 wrote: post #142

Earlier quoted context omitted.

When your engine catches on fire/blows apart on takeoff you want to cut fuel as fast as possible.

Proposed algorithm: If the flight computer thinks the engine looks "normal", then blare an alarm for x seconds before cutting the fuel. I wonder if there have been cases where a pilot had to cut fuel before the computer could detect anything abnormal? I do realize that defining "abnormal" is the hardest part of this algorithm.

The incident with Sully landing in the Hudson is an interesting one related to this. They had a dual birdstrike and both engines were totally obliterated and had no thrust at all, but it came up later in the hearing that the computer data showed that one engine still had thrust due to a faulty sensor, so that type of sensor input can't really be trusted in a true emergency/edge case, especially if a sensor malfunctions while an engine is on fire or something.

As a software engineer myself I think it's interesting that we feel software is the true solution when we wouldn't accept that solution ourselves. For example typically in a company you do code reviews and have a release gating process but also there's some exception process for quickly committing code or making adjustments when theres an outage or something. Could you imagine if the system said "hey we aren't detecting an outage, you sure about that? why don't you go take a walk and get a coffee, if you still think there's an outage in 15 minutes from now we will let you make that critical change".

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