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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)

#61

Just makes me glad how small the consequences are if I have a day of shitty performance at work

Yes. A few years after this event I broke production of some software payment service while working at AirFrance. Some avoidable error not caught during testing and validation. We had to rollback after some time and nobody died nor talk about it.

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

#62
post #20
post #3

Earlier quoted context omitted.

> Unlike most other airliners, the control sticks on Airbus models are not mechanically linked and the pilots cannot directly feel what the other pilot is doing. This is a very bad design - at a bare minimum an incredibly loud and annoying alarm should go off if the pilots are fighting controls, because neither knows what the plane is receiving as an input.

It has been changed after this incident. There is now an alert for dual input. The resulting Airbus system is better than traditional connected yokes, because it doesn't have the unexpected opposite input anymore (with the alert) but it does also have an override switch for the captain's side. Which means you can overpower the first officer with just a button instead of physically having to wrestle for the controls.…

The Dual Input alarm wasn't added, in fact it sounded several times during the Air France flight.

FDR visualization: https://www.youtube.com/watch?v=0a06A78iXnQ

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

#63
post #52

It's tempting to blame the inexperienced first officers, their training, or the CRM failures on this flight, but the blame for this crash has to land squarely on the atrociously bad UX of the Airbus cockpit. Sensory overload and no clear readout of what is actually broken (pitot tube icing in this case) is bad but the fly-by-wire joystick configuration is what really doomed this flight. In Boeing airliners and many o…

Someone in my extended family works at Airbus as an engineer (hence the throwaway account)

When I asked him about this accident, I brought up this specific point - the mechanical non-linkage.

Sure, the Airbus is fly by wire (there are no "mechanics"), but you can still program one joystick to mimic the other joystick, right? As far as I know, the Airbus plane actually averages the inputs..?? [0]

Anyway, he sorta-angrily gave me the same explanation as I just saw posted here as well: it was a crew management issue. (which of course may have played a huge role).

I am not a pilot so I am probably missing something. But he (the Airbus family member) did seem quite defensive about this. What portion was internalized corporate-comm "we are not at fault" reasoning? What portion was engineering hubris of "fly by wire is unquestionably superior to mechanical linkage"?

I don't know. But I do find it strange... and indefensible. When does the average of inputs make sense? I'm open to an explanation. Is there a good one?

---

[0] See https://news.ycombinator.com/item?id=4224707 from 2012.

"This input was averaged (read: canceled) with the other pilot's nose up input."

(and further down in the same sub-thread)

"The AF447 inputs were averaged."

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

#64

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…

Time and time again we learn that people do stupid things under stress. Consider Transair flight 810 [1], in which a simple engine failure during takeoff results in a complete loss of the aircraft when both pilots mistakenly identify the _wrong_ engine as malfunctioning, despite identifying the failure correctly only minutes earlier. OP has an article on that crash too, actually [2]. [1]: https://en.wikipedia.org/wik…

Another very common failure mode, and really all you can do is mandate an SOP that the crew member vocalizes which engine they're turning off, and the other crew member verifies that it's the correct engine.

The other answer to "people do stupid things under stress" is the common maxim that every emergency procedure in every aircraft starts the same way. Somewhere in the cockpit is probably a standard-issue mechanical 8-day clock, and the first thing you do in any emergency is stop and wind the clock. Not because it does anything to the aircraft, precisely the opposite. It makes you stop for a second or two for the "oh shit" moment to pass. Then you analyze what's actually going on. The other saying that's always briefed is "no fast hands in the cockpit." You may need to be expeditious, but you still vocalize what you're doing with your crew or wingman and methodically go through the emergency procedure. You get in a lot more trouble flipping switches willy-nilly based on what you think you have than if you just stop, breathe, and look at what the aircraft is telling you. I still can recite the steps from memory:

- Maintain aircraft control

- Analyze the situation

- Apply the appropriate emergency procedure(s)

- Land when conditions permit

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

#65

Earlier quoted context omitted.

I suppose you've heard it all, like the fact that there are more than 10000 planes currently in the air and we haven't heard about a plane crash for weeks now. If you go to https://globe.adsbexchange.com and zoom out you can see all the planes around the world, flying safely. I suppose the only way through the fear is to fly and realize at the end that you're fine (although obviously IANAP)

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.

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

#66
post #52

It's tempting to blame the inexperienced first officers, their training, or the CRM failures on this flight, but the blame for this crash has to land squarely on the atrociously bad UX of the Airbus cockpit. Sensory overload and no clear readout of what is actually broken (pitot tube icing in this case) is bad but the fly-by-wire joystick configuration is what really doomed this flight. In Boeing airliners and many o…

> It's tempting to blame the inexperienced first officers or their training but the blame for this crash has to land squarely on the atrociously bad UX of the Airbus cockpit. The real problem is that someone who doesn't look at his most critical instrument* in instrument flying conditions, causes a stall, doesn't respond to stall warnings, doesn't communicate, refuses to hand over controls even though he doesn't unde…

Also, the PNFs hesitancy to shout "my controls" and/or hitting the priority button, especially as he moves to pitch the plane down when it was probably still recoverable.

That the off-duty captain standing behind them is the first to vocalize they're at 10000 ft and stalling is indeed not great.

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

#67
post #37

Earlier quoted context omitted.

> But I can't help wondering if some combination of voice stress analysis and measuring pilot coordination might be able to produce a warning that would have prompted the flight crew to see that they had stopped flying in an orderly way. I guess I don't know what you could do with that, flashing another alarm at an already overstressed flight crew seems like it's unlikely to help?

The most likely thing to help in something like this, is for the plane to realize it's going to die, and just take over. And that has usually been the "airbus way", whereas Boeing has more had a notion of throw things to the pilots often enough so they know what they're doing.

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.

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

#68

If you liked this article, definitely consider checking out other articles written by Kyra (Admiral_Cloudberg). She has done a ton of articles on almost all notable (near)crashes, including their root causes, investigations, and subsequent effects on the airplane industry. For some crashes that have interesting causes (at least from an engineering perspective) beyond "maintenance failed to identify a problem before t…

What a great article on TWA 800. My gramps was a retired manager from TWA and when that happened he was all over it calling his buddies still working there. Thanks for the article!

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

#69
post #66

Earlier quoted context omitted.

> It's tempting to blame the inexperienced first officers or their training but the blame for this crash has to land squarely on the atrociously bad UX of the Airbus cockpit. The real problem is that someone who doesn't look at his most critical instrument* in instrument flying conditions, causes a stall, doesn't respond to stall warnings, doesn't communicate, refuses to hand over controls even though he doesn't unde…

Also, the PNFs hesitancy to shout "my controls" and/or hitting the priority button, especially as he moves to pitch the plane down when it was probably still recoverable. That the off-duty captain standing behind them is the first to vocalize they're at 10000 ft and stalling is indeed not great.

He did hit the priority button and say "Controls to the left." Bonin hit his priority button to take back control but didn't say he was taking back control.

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

#70
post #52

It's tempting to blame the inexperienced first officers, their training, or the CRM failures on this flight, but the blame for this crash has to land squarely on the atrociously bad UX of the Airbus cockpit. Sensory overload and no clear readout of what is actually broken (pitot tube icing in this case) is bad but the fly-by-wire joystick configuration is what really doomed this flight. In Boeing airliners and many o…

Armchair amateur, Pitot tube failure is such a frequent occurrence that I’m angry we display any other warning than this one.

- It should have a needle to eject caps on it, so that pilots don’t forget the caps (Brisbane accident, among many),

- The needle should also sense, if not remove, the ice (Air France accident),

- It should wake up the pilots and reset controls to fixed values for the current altitude, since when Pitot tubes fail, autopilot and autothrottle are worse than worthless (they will automatically crash the plane).

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