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The crash of Air France flight 447 (2021)

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Re: The crash of Air France flight 447 (2021)

#101

Post by sambapa »

goles wrote: post #65
ceejayoz wrote: post #33

Earlier quoted context omitted.

Also note that the last deadly airline crash in the US was all the way back in 2009. We've gone 14 years without a single one, which is a pretty remarkable safety record for the FAA and NTSB.

I don’t know if it’s any comfort to scared fliers but even in the incredibly rare circumstances you are involved in a crash? It’s gonna be over quick. It’s gonna be bang, people are gonna scream, you’re gonna be the most scared you’re ever gonna be for like 15-90 seconds and then it’s all gonna be over. That’s if you even get to hear the bang in the first place.

If you are involved in a plane crash then statistically you survive.

So microscopically small chances of something bad happening times not so small chance of dying in a plane crash = nothing to worry about, you have to be incredible lucky to be so unlucky.

Re: The crash of Air France flight 447 (2021)

#102

Post by jmyeet »

itsmartapuntocm wrote: post #10
jmyeet wrote: post #2

It's kind of amazing how many of these accidents can come down to the pilots forgetting the most basic things. In this case, ultimately, the pilot and the co-pilot were exerting opposite controls. One to pull up, one to push the nose down. In a stall you push the nose down to gain aerodynamic lift. That's like Flying 101. But I guess when you panic, the natural instinct of wanting to pull up kicks in when you're rapi…

Are you thinking of Helios Airways Flight 522? That Ethiopian Airlines flight was a hijacking. https://en.wikipedia.org/wiki/Helios_Airways_Flight_522

Sorry, yes I am. Thank you. I guess I saw a few flight disaster things recently and got them mixed up.

Re: The crash of Air France flight 447 (2021)

#103

Post by jcalvinowens »

zerocrates wrote: post #95
jcalvinowens wrote: post #91

The article misses the key takeaway from this incident IMHO. When the controls were pegged at full aft deflection, the stall warning would cease , because instrument readings in the deep stall were considered invalid by the computer. Whenever the pilot would start to push forward to recover, the computer stopped rejecting the readings, and started sounding the stall warning again! So every time the pilot started to d…

This is mentioned in the article.

Only in passing. The dramatized retelling through the first part of the article completely glosses over it.

Re: The crash of Air France flight 447 (2021)

#104

Post by vkou »

skissane wrote: post #78
vkou wrote: post #67

Earlier quoted context omitted.

The plane can't take over when it has no idea of what it's airspeed is. That's what caused this whole chain of problems in the first place.

We expect human pilots to be able to stop the plane from crashing when the airspeed is unknown. If that’s possible for humans, why not for computers?

If a computer could have done it, it would not have needed to have dropped out of normal law to begin with.

When in normal law, the plane pretty much flies itself. When the computer has uncertainty with its sensors, it drops out of normal law, and expects the pilots to fix the problem.

You're asking that the computer, when it is uncertain in its sensors, to the point where it can't fly under normal law, and where the pilots are expected to fix the problem should actively stop the pilots from taking the 'wrong' actions.

What do you think would happen when the pilots are taking the right actions, but the computer's faulty sensors end up preventing them from doing so?

Who is ultimately in charge in a sensors-out situation? The human? Or the computer? Which of these do you believe should have the final say on flight decisions?

----

If you say 'The computer', I'll have to ask you: How well did that work out for the 346 people killed by Boeing's MCAS, which, thanks to a faulty sensor, was utterly convinced that the 737 was too nose-up, and happily flew the damn thing right into the ground, despite the best efforts of the human pilots.

Asking the computer to fly the plane when its sensors are broken is like asking the pilot to fly the plane with no eyes.

Re: The crash of Air France flight 447 (2021)

#105

Post by SoftTalker »

jcalvinowens wrote: post #91

The article misses the key takeaway from this incident IMHO. When the controls were pegged at full aft deflection, the stall warning would cease , because instrument readings in the deep stall were considered invalid by the computer. Whenever the pilot would start to push forward to recover, the computer stopped rejecting the readings, and started sounding the stall warning again! So every time the pilot started to d…

Not a pilot but I believe that pulling the stick back is exactly the wrong thing to do in a stall. The pilot should have instinctively known that pulling back on the stick would not recover a stall. On the other hand, pilots are taught to "trust the instruments" but IIRC the aircraft had no angle of attack indicator, and the airspeed tubes were frozen over. So lots of bad or missing information, contributing to stress and panic, which does strange things to otherwise normal people.

Re: The crash of Air France flight 447 (2021)

#106

Post by quacked »

jandrese wrote: post #99
psunavy03 wrote: post #46

I fly a desk herding cats, I mean devs, for a living now. But as a Navy-trained aviator, this and the Colgan Air mishap in Buffalo always make me cringe. I can't entirely judge the crew, because the human mind is a strange thing that has ways of rationalizing truly abnormal situations and behavior. That said, an obvious Crew Resource Management failure compounded the issues here. That said, I believe aerobatics and o…

Maybe not even acrobatic flying training but glider training. Pilots with glider experience are some of the best performers in emergencies.

I used to fly hang gliders. For almost every issue (except for flying too fast), when you get into trouble in a glider you lower your AoA and increase speed.

Re: The crash of Air France flight 447 (2021)

#108

Post by ghaff »

psunavy03 wrote: post #46

I fly a desk herding cats, I mean devs, for a living now. But as a Navy-trained aviator, this and the Colgan Air mishap in Buffalo always make me cringe. I can't entirely judge the crew, because the human mind is a strange thing that has ways of rationalizing truly abnormal situations and behavior. That said, an obvious Crew Resource Management failure compounded the issues here. That said, I believe aerobatics and o…

Never been anything especially serious fortunately but I lose track of the number of times when something I've seen just didn't square with my current mental model of the physical world (like what day it was to give a trivial example) and, even though I consciously noted the observance, I've basically deep-sixed it into the "that's weird" can.

Re: The crash of Air France flight 447 (2021)

#109

Post by 8ytecoder »

SoftTalker wrote: post #105
jcalvinowens wrote: post #91

The article misses the key takeaway from this incident IMHO. When the controls were pegged at full aft deflection, the stall warning would cease , because instrument readings in the deep stall were considered invalid by the computer. Whenever the pilot would start to push forward to recover, the computer stopped rejecting the readings, and started sounding the stall warning again! So every time the pilot started to d…

Not a pilot but I believe that pulling the stick back is exactly the wrong thing to do in a stall. The pilot should have instinctively known that pulling back on the stick would not recover a stall. On the other hand, pilots are taught to "trust the instruments" but IIRC the aircraft had no angle of attack indicator, and the airspeed tubes were frozen over. So lots of bad or missing information, contributing to stres…

Not a pilot either. And that’s what I learnt playing hours of simulator games. Isn’t gaining airspeed the primary goal?

Re: The crash of Air France flight 447 (2021)

#110

Post by Glawen »

CoconutPilot wrote: post #107

One thing that stands out to me is the incorrect use of the word "law" when referring to flight modes. Is this just a bad translation? Are any native French speakers familiar with the Airbus documentation able to comment if the concepts make more sense in French?

The word loi (law) is indeed used in french controls engineering, not only for planes. See https://fr.m.wikipedia.org/wiki/Loi_de_commande_de_vol

Cannot say if it is good or bad to be honest, I believe Airbus themselves decided on the English term law to translate the french term.

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