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The crash of Air France flight 447 (2021)

admiralcloudberg.medium.com

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

#171

Post by t0mas88 »

bombcar wrote: post #83
t0mas88 wrote: post #20

Earlier quoted context omitted.

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.…

Of course that introduces the problem of "what if the captain is the startled pilot" - can the first office override the captain?

Yes it will announce "priority right", but it's not normal to take control from the captain (and also highly unusual to take control from the first officer outside of training). Unless you're avoiding an immediate safety threat you would normally call out the problem but not take control.

It's a bit different for a training captain like in the video. They know these are the first officer's first landings on the real aircraft, so when things go wrong they take over.

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

#172

Post by DataJunkie »

molenzwiebel wrote: post #18

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…

The article on TWA 800 was excellent, especially for those that don't know much about what happened.

I've read the accident report, a few books, and even some of the conspiracy theories and this is the best "factual" summary.

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

#173

Post by orange_fritter »

benhurmarcel wrote: post #141
throwaway110823 wrote: post #63

Earlier quoted context omitted.

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-angr…

What would you have the system do instead of averaging the inputs? If you have 2 inputs when you should have 1, you warn with a light and sound, and what input do you use in the meantime?

There are plenty of situations where averaging two safe-but-opposite inputs would cause a crash. For instance, if you're holding hands/handcuffed with someone and walking toward a pole, you must both either go left, or both go right. This is a very common scenario in life and we have many solutions for the problem.

In the Air France situation, there's no way for the plane to "know" which pilot's input is correct, so I don't have a good answer, but "just average two drastically different inputs" seems crazy.

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

#174

Post by t0mas88 »

_cenw wrote: post #62
t0mas88 wrote: post #20

Earlier quoted context omitted.

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

Ah thanks. I thought I remembered from ground school that this was added afterwards.

Interesting that the FO flying from the left seat did not recognise that callout as a big thing to react to.

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

#175

Post by srvmshr »

oatmeal1 wrote: post #59
kloch wrote: 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…

I won't like to criticize someone with a different trade skill (much less when they're already dead), but to paraphrase two of my CFI friends, their summary view was "Bonin acted stupidly". He didn't communicate he had controls, kept pulling the stick to nose up. The pilot psyche element had lot to play in this accident. He was sticking to a naive understanding of aerodynamics in panic - which was counterfactual - rather than counting on prior training experience (like what we developers would say an antipattern). Relaying a similar point, his training still wasn't enough to gather situational awareness & apply common-sense instead of a panicky behavior.

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

#176

Post by venusenvy47 »

rsync wrote: post #7

Perhaps these pilots were "Children of the Magenta"[1] ? These AA instructional videos by Captain Vanderburgh are fascinating - even to a non-pilot like myself. They are especially relevant as we dip our toes into automobile auto-pilot and the "automation dependency" that comes along with it. Of particular note in this video: @ 12:30: "... tactily connected to the airplane ..." @ 14:15: "... we see automation depende…

Just FYI, Admiral Cloudberg has an article titled "Children of the Magenta", but it is related to a specific AA 965 crash in 1995.

https://admiralcloudberg.medium.com/children-of-the-magenta-...

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

#177

Post by mb7733 »

jimmaswell wrote: post #168
flerchin wrote: post #156

Earlier quoted context omitted.

Jetstreams are hundreds of kph. Meaning groundspeed can be hundreds of kph off of airspeed. Meaning GPS is a very poor backup airspeed indicator.

It's trivial to calculate true speed from altitude and ground speed. Is the altitude not reliable?

Air speed is relative to the air around the plane, not the ground.

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

#178

Post by bobbylarrybobby »

ghaff wrote: post #108
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.

Holy crap, this. I've been trying to force myself to pay attention to my “that's weird”s but really struggle to do so. Anyone have any tips?

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

#179

Post by matheusmoreira »

brazzy wrote: post #93
kloch wrote: 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, 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. Hard disagree. No matter how bad the UX, there just isn't any conceivable situation where Bonin's pulling up the rudder for minutes on end wasn't suicidally dangerous, or made any sense at all.

I have to agree with you. Even non-pilots who play video games have enough common sense not to do that: they notice that when they climb sharply they lose speed and eventually stall and that when they dive back down it gives them their speed back and allows them to recover.

His inexperience cannot be denied. Must have been terrifying for the pilot when the plane's safeties and automation suddenly disengaged. Uncertainty and panic must have seized him and never let go.

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

#180

Post by srvmshr »

fakedang wrote: post #77
oatmeal1 wrote: post #59

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…

Honestly, part of the mistake is also on Dubois. When flying as a team, it is essential to establish hierarchy and make sure who has authority. As the one with the lesser number of hours, Bonin should have been relegated in favor of Robert. That being said, hierarchy should not be as much of an obstacle that the one in authority disregards the suggestions of the copilot.

Bonin in his panic hit his priority button to take back control but didn't say he was taking back control. He should have announced he has the controls - and it is obvious knowledge to pilots that flight behavior us from the averaged stick inputs. But only when they know both are handling flight surfaces.

If a pilot stubbornly wants to keep control maybe out of desperation or panic - and performs actions which are counterfactual to the knowledge of aerodynamics every pilot is taught, there is no instrument system which can salvage this catastrophe.

["Bonin acted like an idiot" - not my words, but two of my CFI friends, who discuss aviation topics on weekends often over beers.]

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