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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

#691

Post by stravant »

BurningFrog wrote: post #679

As an amateur UI designer I'm really surprised the plane allows a crash to be initiated without as much as an "Are you sure?" check. This is a completely computer run plane, and it surely has enough information to know this is a disastrous thing to do.

There's literally hundreds of such settings. When you get into the combinations there's such a multitude of scenarios that you certainly can't have dedicated code for everything.

I suppose you could have it attempt to run a full forward-looking flight simulation to predict but part of the reason for there being so many controls is to deal with situations where the plane isn't acting like it should be, situations which would invalidate the simulation.

Re: Preliminary report into Air India crash released

#692

Post by bgnn »

arctics wrote: post #662

Throttle control module (TCM) was replaced twice in the past 2019 and 2023 which is not very usual. Now pure speculation, both pilots have long record of flying, you have to literally pull up and move each fuel control switches to cut off. Either one of the pilots did this intentionally or control unit was faulty. Considering past history and pilot experience, my bet is on faulty controls but we will never know.

They can be tested if there's a mechanical failure ifthe switches survived the crash.

Re: Preliminary report into Air India crash released

#693

Post by jahewson »

xlbuttplug2 wrote: post #674
nosianu wrote: post #480

Earlier quoted context omitted.

> if not in the middle of a densely populated city, especially if above a plain or water What is on the ground below does not matter at that point - how far above that ground you are is what is important. More altitude is more time. This flight was less than 200 meters up in the air. Sully's flight that you probably remember, that made a successful emergency landing on the river, was about 860 meters high, giving the…

Okay, maybe there is little hope of making an ideal landing. But the likelihood of it being a fatal accident is significantly reduced without the building in the equation, no?

Given the amount of fuel on board the answer is probably “not by much”.

Re: Preliminary report into Air India crash released

#694

Post by yason »

patch_cable wrote: post #689
yason wrote: post #672

It is known that the switches cannot effectively be flipped by accident. It is known that the switches were set to "cut-off" because they were then later restored to "run", so it was not an electrical fault (i.e. switches pointing to run but reporting cut-off). Pilot dialogue and engine telemetry confirms the cause of power loss was fuel cut-off. The question I can't help but think is how did the pilot realize it was…

I’m more familiar with the 737 (as a hobby, not as a pilot), but for that aircraft the “loss of thrust on both engines” checklist has the start levers as the second item on the list. Note that in the checklist I am looking at the goal is to restart the engines rather than diagnose the failure and that involves these levers. I suspect you’d notice pretty quickly if they were not in the expected location.

Thanks, this is good information. So it then fits the overall picture that they would've actually bumped into these switches in the rush of emergency eventhough they're never expecting the switches to actually be off.

Re: Preliminary report into Air India crash released

#695

Post by ankit219 »

jeswin wrote: post #640

Here's another point of view: https://x.com/BDUTT/status/1944012769323626682 The four Indian pilots on her show are clearly not convinced that the pilots are to blame. As they mention, it's important to know what else was spoken in the cockpit. Quite possible that there's more, and that might have implicated the pilots. However, if that's not the case, this is a very poorly worded report.

This is BBC, they have a history of being uncharitable when it comes to reporting on their erstwhile colonies. Jumping to a conclusion about pilot's fault when the recorded dialogues show both had no idea who cut it off (leaving ground for a possibility of some malfunction) is irresponsible, especially when the report could have been worded better without needing to reach a definitive conclusion.

Both pilots have a long history of flying, a lot of experience, so while there is a chance one of them did it unknowingly, it's a small one in my opinion. Because it's not just a small switch, but a multi step procedure. The reporting on such a sensitive issue has been shocking to say the very least,

Re: Preliminary report into Air India crash released

#696

Post by sillysaurusx »

SAI_Peregrinus wrote: post #629

Assuming this is a murder-suicide and not a mistake or malfunction somehow, it's very damning of the FAA's policy to revoke the pilot's licenses of anyone seeking treatment for mental health issues. This was in India and thus not FAA jurisdiction, but it still would be a case where an untreated mental health issue lead to hundreds of deaths. By making pilots choose between their careers & medical treatment (since the…

First of all, thank you for calling attention to this. You’re absolutely right, despite what others are saying here. That’s why there’s a movement for reforms.

Secondly, yes, it was likely a deliberate action to cut off the fuel switches, as you say.

You are absolutely right that there’s an epidemic in the airline industry that forces pilots to stay quiet rather than risk their careers if they’re dealing with mental health issues.

In a sibling comment: “shouldn’t they be given alternate career paths?” No. Perpetuating the myth that people with mental health issues are somehow broken beyond repair is mistaken. Current policy lead directly to that one fellow to lock the cockpit door and slam the plane into a hillside. If Air India 171 has any chance of being a mental health issue today, it should be highlighted and explored. You’re exactly right to be doing that, and thank you.

Anyone who disagrees with this should watch https://youtu.be/988j2-4CdgM?si=G39BwNy1zJEeUi2k. It’s a video from a well-respected pilot. The whole point of the video is that aviation forces people to conceal their problems instead of seek treatment, and that this has to change.

Re: Preliminary report into Air India crash released

#697

Post by blincoln »

gmokki wrote: post #681
yason wrote: post #672

It is known that the switches cannot effectively be flipped by accident. It is known that the switches were set to "cut-off" because they were then later restored to "run", so it was not an electrical fault (i.e. switches pointing to run but reporting cut-off). Pilot dialogue and engine telemetry confirms the cause of power loss was fuel cut-off. The question I can't help but think is how did the pilot realize it was…

I would assume that the engines cur of due to fault in the shared control system. And to restore power the pilots toggled the switches to off and then back on to get them running again. Hopefully the timestamps tell if the engines lost power before switches were turned off? Or is there some time window that was not recorded due to the lost power to systems?

This is one of the first scenarios that came to mind for me as well.

i.e. hypothetically, no one flipped the switches to cutoff initially, but a glitch in a computer component caused the same effect, including some indication (a status light?) that the switches were in cutoff state. One of the pilots saw the indication, and asked the other. The other (truthfully) said they hadn't. Ten seconds of confusion later, one of them flipped the switches off and back on to reset the state to what it should have been.

That assumes that the switches are part of a fly-by-wire system, of course. I am not an aircraft engineer, so maybe that's not a safe assumption. But if they're fly-by-wire, seems like there might not be a way to know for sure without cockpit video, because the logging system might only log an event when the switches cause the state to change from what the computer thinks the current state is, not necessarily when the switches change to the state the computer thinks they're already in.

Someone bumping the switches accidentally seems worthy of investigation as well, given the potential for an "Oops! No locking feature! Our bad!" scenario on the part of Boeing that's mentioned in the BBC article.

Re: Preliminary report into Air India crash released

#698

Post by sillysaurusx »

noqc wrote: post #661
SAI_Peregrinus wrote: post #629

Assuming this is a murder-suicide and not a mistake or malfunction somehow, it's very damning of the FAA's policy to revoke the pilot's licenses of anyone seeking treatment for mental health issues. This was in India and thus not FAA jurisdiction, but it still would be a case where an untreated mental health issue lead to hundreds of deaths. By making pilots choose between their careers & medical treatment (since the…

The murder suicide angle isn't particularly worthy of assumption yet. Have you ever put your phone in the fridge? Pilots deactivate the fuel cutoff at the end of the final taxi to the gate. This makes flipping these switches a practiced maneuver , capable of being performed without conscious thought, regardless of whether they came with safety locks installed. Brain farts are a real phenomenon, and an accidental fuel…

If you were correct, the only situation it would happen in is when the pilot flying asks for X to happen, and the pilot monitoring instead does Y. Pilots don’t just randomly reach over and screw with the controls. Everything is called out, and as far as I know there were no callouts here (e.g. “gear up”).

This is a bit like someone parking their car, pulling the handbrake, turning off the car and putting their keys in their pocket, then arguing that it’s a practiced maneuver because it happens at the end of every car ride.

Re: Preliminary report into Air India crash released

#699

Post by histriosum »

noqc wrote: post #661
SAI_Peregrinus wrote: post #629

Assuming this is a murder-suicide and not a mistake or malfunction somehow, it's very damning of the FAA's policy to revoke the pilot's licenses of anyone seeking treatment for mental health issues. This was in India and thus not FAA jurisdiction, but it still would be a case where an untreated mental health issue lead to hundreds of deaths. By making pilots choose between their careers & medical treatment (since the…

The murder suicide angle isn't particularly worthy of assumption yet. Have you ever put your phone in the fridge? Pilots deactivate the fuel cutoff at the end of the final taxi to the gate. This makes flipping these switches a practiced maneuver , capable of being performed without conscious thought, regardless of whether they came with safety locks installed. Brain farts are a real phenomenon, and an accidental fuel…

> The report is actually a little cagey about whether the locks were properly installed on these switches. Said locks are supposedly optional.

The locks/gates on the switches are definitely NOT optional. There was an SAIB about some switches that may have been installed improperly. It didn't result in an AD, which likely means the extent was limited or potentially even nil.

The switches were moved to cutoff with a one second delay between the first and second switch. That's pretty suggestive of deliberate movement. I've flown a Max9 simulator, which has the same switches. Moving one of them by accident would be impossible, let alone two of them.

I agree with not jumping to conclusions about the pilots and possible motives or circumstances, but I will bet a lot of money that the switches were just fine.

The CVR will likely have audio of the switch movement to confirm as well.

Re: Preliminary report into Air India crash released

#700

Post by blincoln »

demondlee wrote: post #685
zamadatix wrote: post #130

Earlier quoted context omitted.

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 co…

Double engine failure was confirmed, not disproven. RAT deployment was confirmed, not disproved. Pilot error, confirmed, not disproven. Preliminary and final aviation reports are mostly guesses.

I don't think it's fair to say that pilot error is confirmed yet. It seems like a reasonable hypothesis, but what if the electronics glitched out and acted as though the cutoff switches had been flipped (the first time), even if they hadn't? All of the currently-disclosed facts still line up with that scenario IMO.
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