1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  

What Really Happened Aboard Air France 447

Discussion in 'Off Topic [BG]' started by P. Aaron, Dec 18, 2011.


  1. P. Aaron

    P. Aaron Supporting Member

  2. Jinro

    Jinro

    Oct 9, 2011
    West TN
    Most aircraft (at least the one's I've flown) have something called "Pitot Heat" which prevents the airspeed sensors from icing over. I've never been in an Airbus, but surely it should have one as well. Engaging that switch probably would have prevented this all. Some basic flight planning would have probably helped too.
     
  3. ()smoke()

    ()smoke()

    Feb 25, 2006
    Dallas
    heavy article
     
  4. Big_Daddy

    Big_Daddy

    Nov 24, 2010
    Central Alberta
    It's strange reading something like that. Going over the last moments of their life. And then they just cease to exist... Heavy article. Thanks for sharing.
     
  5. Johnny Fila

    Johnny Fila Formerly "The Crusader" Supporting Member

    Nov 21, 2004
    Elmont, NY (near NYC)
    nothing short of terrifying
     
  6. Scary stuff :(
     
  7. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    Fascinating article, though chilling. I saw a documentary on Netflix a few months ago on this topic.

    I hope this leads to some improved training regimens, particularly on dealing with flight situations that depart from normal law. Increasingly automated flight control and management technology is great, but it also means that situations where the system gives up and goes manual are even further outside the normal envelope. It would be a crime to fail to learn important lessons from this disaster.
     
  8. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    I think the pitot heat is on constantly.
     
  9. Tituscrow

    Tituscrow Banned

    Feb 14, 2011
    NW England
    What's equally terrifying is that I live about 5 miles from where Airbus make their wings, and I reckon 1 in 5 of the local community are employed there. And most of them I wouldn't trust to wire a plug.

    Unsettling stuff.
     
  10. Johnny Fila

    Johnny Fila Formerly "The Crusader" Supporting Member

    Nov 21, 2004
    Elmont, NY (near NYC)
    yes but, in Airbus' defense, it was all the pilots fault.
     
  11. Tituscrow

    Tituscrow Banned

    Feb 14, 2011
    NW England
    Oh I know that. It was just a bit of a frivolous side-related comment. Though I do say a little Hail Mary every time I get on an Airbus.
     
  12. Jinro

    Jinro

    Oct 9, 2011
    West TN
    But if the pitot tubes froze over, that would imply mechanical/technical failure of the heating system, while the article states that there were no mechanical/technical failures, just pilot error.

    What about the de-ice system? Would Pitot Heat be included in that? I was under the assumption that de-ice was for wings and control surfaces while Pitot Heat was a separate switch, and the article did mention that they didn't activate the de-ice system until the pitot tubes were frozen.
     
  13. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    At the time of the crash, Airbus was in the midst of a service campaign to replace the pitot probes. IIRC, there was a problem with the geometry of the older tube that tended to induce icing.

    I believe de-icing systems are usually for wings, slats, ailerons, etc.
     
  14. I've spoken with aerospace engineering professor who had early access to the flight recorder data for analysis. There were definitely some issues with the control electronics - specifically integral windup.

    Pilots were pushing down on the control in an attempt to increase speed - but the plane still had a positive angle of attack (unknown to the pilots) because their stick interaction was only unwinding the integrator not actually nosing the plane down.
     
  15. Bredian

    Bredian

    Apr 22, 2011
    The problem was not pitot heat, but 2 pilots not knowing what each other was doing with the stick - there is a significant difference in design between this Airbus and Boeing.... one pilot was pulling back on the stick, the other could not "feel" it. The most junior pilot was making a mistake and noone could see or feel it (because the controls weren't designed to transmit that).

    The computer "averages" their inputs - FUBAR.

    This is a pretty good case to show how a programmer/designer who is not a pilot, is not competent to design the system. Prove me wrong. This is huge problem with IT.

    While they'll blame this on pilot error, this is a system design error, a training error.
     
  16. Definitely a system design error combined with lack of training in dealing with the "manual" mode which wasn't actually completely manual.

    Also, the control system seems to have had something to do with his choices in pulling back or pushing down - mostly due to a stall indicator which was DISABLED below a certain air speed(to avoid alarm on takeoff and landing).

    So what was happening is they were in a stall condition, but pulling UP on the stick made the stall warning go away - because pulling up on the stick caused the speed to decrease BELOW the speed at which the stall warning disabled... and pushing forward on the stick increased speed (whenever they managed to unwind the integrator in the control loop) causing the stall warning to reappear.

    Combine that with the fact that "manual" wasn't actually manual but was still dealing with integrator windup from the control system...
     
  17. Johnny Fila

    Johnny Fila Formerly "The Crusader" Supporting Member

    Nov 21, 2004
    Elmont, NY (near NYC)
    me too.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.