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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)

#21

Post by nocoiner »

moralestapia wrote: post #15

What an amazing article. I know comments here are meant to be more substantial, but this is truly one of the best written content I've ever come across. My most sincere admiration and thank you notes to the author for putting all of this together in such a great way!

She writes one of these a week, and they’re all very high quality. I highly recommending subscribing. Seeing the new post is always one of the week’s highlights, just like how getting the “Money Stuff” edition is a highlight of every weekday morning (er, early afternoon).

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

#22

Post by formerly_proven »

bombcar wrote: post #3
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…

> 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.

https://safetyfirst.airbus.com/app/themes/mh_newsdesk/docume...

Section 6

> When a dual input situation is detected, the two green priority lights located on the cockpit front panel flash simultaneously.

> After the visual indication has been triggered, a synthetic voice “DUAL INPUT” comes up every 5 sec, as long as the dual input condition persists.

According to Wikipedia, this warning system worked as intended:

> Confused, Bonin exclaimed, "I don't have control of the airplane any more now", and two seconds later, "I don't have control of the airplane at all!"[42] Robert responded to this by saying, "controls to the left", and took over control of the aircraft.[83][44]

> He pushed his side-stick forward to lower the nose and recover from the stall; however, Bonin was still pulling his side-stick back. The inputs cancelled each other out and triggered an audible "dual input" warning.

> ...

> Bonin heard this and replied, "But I've been at maximum nose-up for a while!" When Captain Dubois heard this, he realized Bonin was causing the stall, and shouted, "No no no, don't climb! No No No!"[85][44]

> When Robert heard this, he told Bonin to give him control of the airplane.[2] In response to this, Bonin temporarily gave the controls to Robert.[44][85][2] Robert pushed his side-stick forward to try to regain lift for the airplane to exit the stall. However, the aircraft was too low to recover from the stall. Shortly thereafter, the ground proximity warning system sounded an alarm, warning the crew about the aircraft's imminent crash with the ocean.

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

#23

Post by mrtksn »

boredemployee wrote: post #8

I hate me for watching the news about it on that time. That's the flight that seeing all the details about on television gave me the fear of flying that I have these days, specially when above the ocean. I just can't overcome this.

The real scare accident for me is the Helios flight 552: https://en.wikipedia.org/wiki/Helios_Airways_Flight_522

Due to maintenance error, everyone in the plane including the crew black out of hypoxia and crash on the land. There are horrific pictures from the site.

What made me not being afraid of flying was to get familiar with the technicalities of the flights, it's less scary the more you understand it.

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

#24

Post by markus_zhang »

Does anyone think lack of sleep is the major contributor of this event, or the invalidation of all three speed sensors?

I think we do test pilots for alcohol and drug before a flight, but can we also test them for reaction and a couple of hazard scenarios? Do you think it is too much?

About the sensors, is there any inexpensive way to increase the heat or anything to prevent it from happening again?

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

#25

Post by t0mas88 »

dabluecaboose wrote: post #5
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…

Even as a flying novice, I was screaming to myself when they kept trying to pull up in a stall. I guess there had to have been some element of panic clouding their judgement, which is why pilots need to drill routine into their head so hard.

In normal law an Airbus doesn't stall with full back stick, that would just result in maximum AoA not a stall.

In this case it had degraded to loose some of those protections due to icing of the sensors.

That was confusing to the junior co-pilot, and they skipped basic procedures on who has control resulting in opposite inputs and a loss of control.

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

#26

Post by Tronno »

markus_zhang wrote: post #24

Does anyone think lack of sleep is the major contributor of this event, or the invalidation of all three speed sensors? I think we do test pilots for alcohol and drug before a flight, but can we also test them for reaction and a couple of hazard scenarios? Do you think it is too much? About the sensors, is there any inexpensive way to increase the heat or anything to prevent it from happening again?

Re your last question, the article states Air France was in the middle of upgrading the pitot tubes across its fleet when the accident happened.

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

#27

Post by t0mas88 »

markus_zhang wrote: post #24

Does anyone think lack of sleep is the major contributor of this event, or the invalidation of all three speed sensors? I think we do test pilots for alcohol and drug before a flight, but can we also test them for reaction and a couple of hazard scenarios? Do you think it is too much? About the sensors, is there any inexpensive way to increase the heat or anything to prevent it from happening again?

Every six months we go in the simulator and practice all kinds of failures and disasters.

But lack of sleep is a real issue. Even more on the US side since rest rules are worse than European. Somehow it doesn't get the attention it deserves.

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

#28

Post by roywiggins »

andyjohnson0 wrote: post #16

> A brief interruption to their airspeed indications, lasting less than a minute, had thrown two trained Air France pilots into a state of paralyzed agitation. I'm generally suspicious of technical solutions to human-factors problems. 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 s…

> 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?

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

#29

Post by [deleted] »

andyjohnson0 wrote: post #16

> A brief interruption to their airspeed indications, lasting less than a minute, had thrown two trained Air France pilots into a state of paralyzed agitation. I'm generally suspicious of technical solutions to human-factors problems. 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 s…

[deleted]
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