←back to thread

Preliminary report into Air India crash released

(www.bbc.co.uk)
314 points cjr | 8 comments | 11 Jul 25 20:23 UTC | HN request time: 0.949s | source | bottom
Show context
fsckboy ◴[11 Jul 25 23:07 UTC] No.44537714[source]▶
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 youtube pilot/analysts I watch but dismissed as unlikely.
replies(9): >>44537808 #>>44538063 #>>44538104 #>>44538161 #>>44538361 #>>44540315 #>>44541363 #>>44541712 #>>44541805 #
1. dyauspitr ◴[12 Jul 25 00:58 UTC] No.44538361[source]▶
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.
replies(2): >>44538978 #>>44541005 #
2. WalterBright ◴[12 Jul 25 03:10 UTC] No.44538978[source]▶
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.

replies(2): >>44539563 #>>44540677 #
3. dyauspitr ◴[12 Jul 25 05:30 UTC] No.44539563[source]▶
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.
replies(1): >>44540025 #
4. WalterBright ◴[12 Jul 25 07:23 UTC] No.44540025{3}[source]▶
If the ground you are over is a good landing spot, your best chance is to cut off the fuel to that engine ASAP.
5. russdill ◴[12 Jul 25 09:38 UTC] No.44540677[source]▶
If you read through the boeing procedures, if an engine fails just after take off you delay cutting throttle or hitting the cutoff until you have positive climb and pass a certain altitude. Specifically because a mistake here would be so incredibly catastrophic. The following number of steps and verbal cross checks for then shutting down the engine are quite daunting. Not something applicable here, but still interesting to learn about
replies(2): >>44541715 #>>44541999 #
6. bestouff ◴[12 Jul 25 10:40 UTC] No.44541005[source]▶
On an Airbus yes, engines won't stop if the thrust lever isn't on "idle".

Not so much on a Boeing.

7. jacquesm ◴[12 Jul 25 12:52 UTC] No.44541715{3}[source]▶
This is such a funny comment. Of course you have no clue why it is funny. But that makes it all the more funny. Eventually you'll figure it out though.
8. interestica ◴[12 Jul 25 13:40 UTC] No.44541999{3}[source]▶
That’s absolutely applicable here. It means that an engine cutoff shouldn’t be allowed at all during certain parts of flight. It’s not crazy to think that a design fix would be to prevent those engagements during certain parts of takeoff (a certain window). It’s fly by wire anyway so it could presumably be done programmatically.

MCAS was basically made to prevent user input that would send the plane into a dangerous angle. The computer overrode the inputs. So there’s precedent for something like it.