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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

#251

Post by aerospace83 »

zahlman wrote: post #159
aerospace83 wrote: post #132

Earlier quoted context omitted.

[flagged]

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…

> 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.

Re: Preliminary report into Air India crash released

#252

Post by mcpeepants »

adrianmonk wrote: post #222
rogerrogerr wrote: post #100

Earlier quoted context omitted.

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

I don't think the theory is that the muscle memory sequences resemble each other. Instead, it's that because muscle memory allows you to do things without thinking about it, you can get mixed up about which action you meant to perform and go through the whole process without realizing it.

Is actuating the fuel cutoff switches something that is done routinely in these aircraft, to the extent it could reasonably become muscle memory?

ETA: downthread it is mentioned that these switches are used on the ground to cut the engines

Re: Preliminary report into Air India crash released

#253

Post by WalterBright »

dyauspitr wrote: post #162
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…

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.

Re: Preliminary report into Air India crash released

#254

Post by WalterBright »

fsckboy wrote: post #128
rogerrogerr wrote: post #100

Earlier quoted context omitted.

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 dow…

My editor is MicroEmacs, which I've been using since the 1980s. I no longer remember what the commands are, but my fingers do.

I remember once writing a cheat sheet for the commands by looking at what my fingers were doing.

Re: Preliminary report into Air India crash released

#255

Post by ekianjo »

lanna wrote: post #164
decimalenough wrote: post #155

Earlier quoted context omitted.

Third, since there's no other plausible explanation for this and China has classified the report. https://en.wikipedia.org/wiki/China_Eastern_Airlines_Flight_...

Fourth? https://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_370#M...

We dont know about that one at all.

Re: Preliminary report into Air India crash released

#256

Post by WalterBright »

dboreham wrote: post #171
baseballdork wrote: post #125

Earlier quoted context omitted.

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.

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

Remember the "surging" incidents where the driver insisted he was stepping on the brake but was actually stepping on the gas?

Re: Preliminary report into Air India crash released

#257

Post by ekianjo »

ssl232 wrote: post #35
bgwalter wrote: post #25

Earlier quoted context omitted.

Does the Flight Data Recorder consider the physical position of the fuel switches or does it get the information from some fly-by-wire part that could be buggy? The conversation would suggest that the switches were in CUTOFF position, but there is also a display that summarizes the engine status. There is no conversation that mentions flipping the switch to RUN again. EDIT: Why is there no Cockpit Video Recorder? The…

> EDIT: Why is there no Cockpit Video Recorder? The days of limited storage are over. Pilots unions are dead against it.

And Pilots end up dead because of it.

Re: Preliminary report into Air India crash released

#258

Post by ekianjo »

karlgkk wrote: post #242
nikanj wrote: post #60

Earlier quoted context omitted.

Airlines are decades behind on tech. You can get satellite internet almost anywhere on the planet and GPS can give you ten-foot accurate positioning, but we've still _lost_ planes because we haven't mandated a system that sends the realtime position of the plane over the satellite internet. The days of limited storage are still going strong in the industry.

There are reasons they don’t. This is a deceptively difficult problem Cost is a big one (satellite data is still quite a bit more expensive than you think, especially with many stations) And by stations, I mean aircraft. There are a TON. Current constellations probably wouldn’t even be able to handle half the current aircraft transmitting all at once. Bandwidth, in the physical sense, becomes a limiting factor Covera…

> Cost is a big one (satellite data is still quite a bit more expensive than you think, especially with many stations)

You get free Starlink on several airlines now, so won't that be a solved problem soon?

Re: Preliminary report into Air India crash released

#259

Post by WalterBright »

1970-01-01 wrote: post #163

It's safe to state these fuel cutoff switches aren't to be touched in-flight unless the word 'fire' is said beforehand. Even then, you only perform fuel cutoff for the flaming engine. If the copilot was busy with takeoff, there is exactly one other person in the entire world that could have flipped both switches. We may never know which one flipped them back.

Fire isn't the only instantly severe problem with engines. Another is violent shaking if, say, part of the rotating assembly came off.

Re: Preliminary report into Air India crash released

#260

Post by anonymousiam »

rogerrogerr wrote: post #250
unyttigfjelltol wrote: post #210

Earlier quoted context omitted.

In that case, it could be true both that neither pilot manipulated the switch and that the system recorded a dual fuel cutoff.

Then why do we see the pilots notice the cutoff, move the switches back, and the engines respond as expected? The switched cannot move themselves. We’d expect to hear more commentary and confusion if the cutoff was active and the switches still in Run.

There would have likely been an indication on the glass cockpit displays that the fuel had been cut off, perhaps the pilot flying noticed this and asked the captain.
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