What really happened aboard Air France 447 • Hacker News Board

Re: What really happened aboard Air France 447

#91

Post by jonah » Thu, Dec 08, 2011, 6:40 AM UTC

reledi wrote: post #59

sliverstorm wrote: post #43

Earlier quoted context omitted.

Ah, I was not aware they already could. My next question is why not make themselves de-ice better? This maybe seems trollish or silly, but in all seriousness, if your sensors aren't good enough, first rule out improving the sensors before you try to compensate with the system.

I agree. I know little about aviation, but wouldn't it be better if the sensors would automatically de-ice themselves rather than only being de-iced at the pilots' command?

I believe they're continually heated.

At least every one I've seen is labeled "heated probe" or the like which probably wouldn't be necessary if they had to be manually de-iced.

http://www.flightglobal.com/blogs/flightblogger/pitot-tubes_...

Re: What really happened aboard Air France 447

#92

Post by snowwrestler » Thu, Dec 08, 2011, 6:43 AM UTC

Klinky wrote: post #30

Co-pilot Robert, after finally getting full control back from Co-pilot Bonin: "Damn it, we're going to crash... This can't be happening!" Co-pilot Bonin, who had been pulling back & stalling the plane during the crisis: "But what's happening?" Pretty much sums it up. I am thinking that perhaps Bonin had shellshock & may not have even realized he was holding the stick back. Perhaps the more experienced Robert didn't t…

I think the simplest solution to the mismatched stick issue is to use servo motors to replicate the old situation--the movement of each stick mirrors the movements of the other.

A pilot wouldn't have to look for some stick position display, or indicator light, if they can easily feel the deflection of the stick.

Re: What really happened aboard Air France 447

#93

Post by deepGem » Thu, Dec 08, 2011, 6:44 AM UTC

What really intrigues me is the fact that the captain didn't take control of the plane after returning from his nap. If a respected pilot with 11,000 flying hours to his credit made that mistake, I can't imagine what his mind must have gone through during that time.

Re: What really happened aboard Air France 447

#94

Post by nodesocket » Thu, Dec 08, 2011, 6:45 AM UTC

Klinky wrote: post #30

Co-pilot Robert, after finally getting full control back from Co-pilot Bonin: "Damn it, we're going to crash... This can't be happening!" Co-pilot Bonin, who had been pulling back & stalling the plane during the crisis: "But what's happening?" Pretty much sums it up. I am thinking that perhaps Bonin had shellshock & may not have even realized he was holding the stick back. Perhaps the more experienced Robert didn't t…

This one feature may have prevented the crash.

A indicator light, saying the plan is in "alternate law" mode, and SHIT can go wrong, very quickly.

Also an alarm in the pilot resting area that would relay when warnings are detected like stall or switching to alternate law.

Re: What really happened aboard Air France 447

#95

Post by _sh » Thu, Dec 08, 2011, 6:47 AM UTC

jrockway wrote: post #71

Klinky wrote: post #30

Co-pilot Robert, after finally getting full control back from Co-pilot Bonin: "Damn it, we're going to crash... This can't be happening!" Co-pilot Bonin, who had been pulling back & stalling the plane during the crisis: "But what's happening?" Pretty much sums it up. I am thinking that perhaps Bonin had shellshock & may not have even realized he was holding the stick back. Perhaps the more experienced Robert didn't t…

- Delineate command better, e.g. Captain, Co-pilot #1, Co-pilot #2 so that who is in charge is clear. This antiquated idea has killed many more people than it would have saved in this case. Read about CRM: http://en.wikipedia.org/wiki/Crew_resource_management I think a classic example is: http://en.wikipedia.org/wiki/Avianca_Flight_52 The plane crashed because it burned all of its fuel in a holding pattern waiting to…

An additional case that I know about, the Tenerife airport disaster: http://en.wikipedia.org/wiki/Tenerife_airport_disaster

Quoting:

  Speculation regarding other contributing factors includes:
    The flight engineer's apparent hesitation to challenge Van Zanten
    further, possibly because Captain Van Zanten was not only senior in rank,
    but also one of the most able and experienced pilots working for the airline.

  As a consequence of the accident, sweeping changes were made to
  international airline regulations and to aircraft... Hierarchical
  relations among crew members were played down. More emphasis was
  placed on team decision-making by mutual agreement.

Re: What really happened aboard Air France 447

#96

Post by jarek » Thu, Dec 08, 2011, 6:48 AM UTC

jrockway wrote: post #80

jarek wrote: post #75

Earlier quoted context omitted.

I wonder if in a couple of decades we'll look back at pitot tubes and wonder what the hell we were thinking using such a fragile solution. (Of course, in a couple of decades we'll probably have a much more accurate external method of finding out speed/airspeed.)

It's hard to measure how fast you're going through the air without being able to sample the air. Pitot tubes are just the tubes that bring the air to the inside of the plane to be sampled; nothing more.

I mean, I know the physics behind pitot tubes, but I wonder if we'll come up with a better way of measuring this. Something like measuring deflections of a thousand tiny rods on the plane skin. Still vulnerable to icing and other mechanical damage, I suppose.

Maybe we'll just have really accurate GPS and beam external local instantaneous wind-speed measurements to the plane.

Re: What really happened aboard Air France 447

#97

Post by jrockway » Thu, Dec 08, 2011, 6:50 AM UTC

vacri wrote: post #83

jrockway wrote: post #71

Earlier quoted context omitted.

- Delineate command better, e.g. Captain, Co-pilot #1, Co-pilot #2 so that who is in charge is clear. This antiquated idea has killed many more people than it would have saved in this case. Read about CRM: http://en.wikipedia.org/wiki/Crew_resource_management I think a classic example is: http://en.wikipedia.org/wiki/Avianca_Flight_52 The plane crashed because it burned all of its fuel in a holding pattern waiting to…

Your link doesn't say that there isn't a clear chain of command, it says that there should be a culture that allows professional disagreement or calling to attention. Just because the captain is declared top dog doesn't mean that protocol demands subordinates must remain quiet.

Yes, the link doesn't say that, but research further and you'll find that the concept of a hierarchy is what CRM aims to eliminate. It's the First Officer's job to take the flight controls from the captain if the FO thinks the captain is doing something dangerous. Not to ask for permission, but to immediately do. This goes against the concept of a hierarchy, but is why they put two sets of controls up there.

Re: What really happened aboard Air France 447

#98

Post by akira2501 » Thu, Dec 08, 2011, 6:58 AM UTC

anrope wrote: post #79

donaldc wrote: post #20

Having multiple joysticks that can be in different positions at the same time and yet all simultaneously affect the flight of the Airbus is a serious design flaw.

Up to this point, the situation was playing out in a sadly too common case of pilot error, pilot inexperience, which makes up a huge portion of aviation accidents. When I read about the dual input averaging, I literally exclaimed "what?!". I can't believe that, for all the strict standards that flight control software must meet, nobody called this out as a dangerous idea?

Precisely.. I'd also like to know under what circumstances this would actually be used, and be a useful safety feature to have implemented.

At the very least, there should be a significant warning in the cockpit when "dual input" mode is active. That is an incredibly dangerous "feature."

Re: What really happened aboard Air France 447

#99

Post by jforman » Thu, Dec 08, 2011, 6:58 AM UTC

Klinky wrote: post #30

Co-pilot Robert, after finally getting full control back from Co-pilot Bonin: "Damn it, we're going to crash... This can't be happening!" Co-pilot Bonin, who had been pulling back & stalling the plane during the crisis: "But what's happening?" Pretty much sums it up. I am thinking that perhaps Bonin had shellshock & may not have even realized he was holding the stick back. Perhaps the more experienced Robert didn't t…

- Add a display that shows the current positions of both control sticks. Add an alarm when the two sticks are not within a certain margin of the each other, if both are engaged. Such as if one is full forward & the other is full back.

This was my first thought as well. Confusion in one pilot was allowed to cause confusion in the second pilot, because he didn't realize that his partner was doing something unexpected and incorrect. If you make sure a pilot can always detect inconsistent reaction in a co-pilot, you can keep them in sync and prevent spreading confusion. An alarm when the two pilots are out of sync seems like a pretty straightforward benefit.

Re: What really happened aboard Air France 447

#100

Post by alexbell » Thu, Dec 08, 2011, 7:11 AM UTC

rguzman wrote: post #37

maeon3 wrote: post #27

Pilot stalls the plane out of panic to get out of the storm, ignoring 75 reminders that you are stalling and losing altitude, does nothing to remedy the stall until it is too late. I expect blunders like that from drunk drivers.

way too easy for you to say without being in the situation. heavy turbulence, no visibility, confusing situation, very likely that he was disoriented, operating a very complex set of computer programs hooked up to a very complex set of physical controls that have a myriad of potential configurations and points of failure while trying to debug it at the same time in a panic and making quick decisions. from his vantage…

The not pushing forward while stalling really does say to me by the time they thought to analyze the situation, they were in a state of absolute panic. I would be curious to know if any of the flight crew were military trained, or if all came from a civilian flight instruction background?