Tutti
← Back to Squawk list
Final Air France crash report says pilots failed to react swiftly
(CNN) -- A series of errors by pilots and a failure to react effectively to technical problems led to the crash of Air France Flight 447, France's Bureau of Investigation and Analysis said Thursday in its final report on the disaster. The Brazil-to-France flight plunged into the Atlantic Ocean on June 1, 2009, killing all 228 people on board. (edition.cnn.com) Altro...Sort type: [Top] [Newest]
Popular Science or Mechanics did have a really good article on this that detailed the settings and voice recorder. According to their report, the pilot continued trying to climb during the stall. The pilot and copilot's sticks work independently from each other if my memory serves me correctly.
A lengthy investigation and report could have been summed up in a relatively short paragraph. The crew failed to recognize the most basic aerodynamic phenomenon since fixed wing flying machines were invented, i.e. stall of the main lifting airfoil, the wing. Training of AF crews apparently was lacking severely in basic aero and way over done on believing all those bells and whistles as the be all end all for handling the machine. Seat of the pants flying and judgement is still applicable no matter how many computers there are to supposedly "help" the pilot.
There's a huge difference between mach buffet when approaching transonic speed for "conventional" machines of which the A330 is one, and airframe buffet associated with wing stall. Mach buffet is essentially non-discernible on today's swept wing jet transports. Mach tuck upset is a different story. Fortunately for most, like the A330, airframe buffet associated with wing stall is still very discernible.
When the pitot tube was blocked the airspeed indicator essentially became an altimeter so the speed went off the chart. The autopilot disconnected as advertised with an ADC input of increasing speed. The pilot in command apparently believed the high speed indication which can occur obviously in a region of turbulent and sudden headwind gusts. So he pulled up the nose to climb and reduce the speed while presumably reducing power, all of which was a perfect setup in the high altitude thin atmosphere environment for what followed: stall, deep stall, a high altitude upset as it's often called, with accompanying airframe buffet and an ensuing sink rate approaching 10,000fpm as the nose was held high (poor judgement). Holding the nose high obviously was doing nothing to reduce the high ROD nor the faulty high speed indication with rapidly decreasing altitude, nor the clue of aerodynamic stall resulting in continuous airframe buffet. Thus the classic last words were heard on this like so many other CVRs in the final seconds: "Ah shit, we're gonna crash."
It was all totally avoidable especially since the A330 had a history of pitot tubes icing up in cruise which begs the question: What's up with the pitot heat on that machine? Yeah, it's too easy to blame dead guys but what else can you do when the facts speak loudly that they probably had their heads up and locked on this one - maybe because they like so many others these days were digital age slaves who believe that if it comes out of a computer, it can't be wrong!
There's a huge difference between mach buffet when approaching transonic speed for "conventional" machines of which the A330 is one, and airframe buffet associated with wing stall. Mach buffet is essentially non-discernible on today's swept wing jet transports. Mach tuck upset is a different story. Fortunately for most, like the A330, airframe buffet associated with wing stall is still very discernible.
When the pitot tube was blocked the airspeed indicator essentially became an altimeter so the speed went off the chart. The autopilot disconnected as advertised with an ADC input of increasing speed. The pilot in command apparently believed the high speed indication which can occur obviously in a region of turbulent and sudden headwind gusts. So he pulled up the nose to climb and reduce the speed while presumably reducing power, all of which was a perfect setup in the high altitude thin atmosphere environment for what followed: stall, deep stall, a high altitude upset as it's often called, with accompanying airframe buffet and an ensuing sink rate approaching 10,000fpm as the nose was held high (poor judgement). Holding the nose high obviously was doing nothing to reduce the high ROD nor the faulty high speed indication with rapidly decreasing altitude, nor the clue of aerodynamic stall resulting in continuous airframe buffet. Thus the classic last words were heard on this like so many other CVRs in the final seconds: "Ah shit, we're gonna crash."
It was all totally avoidable especially since the A330 had a history of pitot tubes icing up in cruise which begs the question: What's up with the pitot heat on that machine? Yeah, it's too easy to blame dead guys but what else can you do when the facts speak loudly that they probably had their heads up and locked on this one - maybe because they like so many others these days were digital age slaves who believe that if it comes out of a computer, it can't be wrong!
Paul,
The FDR clearly shows airspeed indications going down, not up, from aabout 275 knots to about 60 knots (e.g., page 22 of the final report). This would seem to rule out a concern about overspeed as an explanation for the PF to make "abrupt and excessive"nose-up control inputs.
The FDR clearly shows airspeed indications going down, not up, from aabout 275 knots to about 60 knots (e.g., page 22 of the final report). This would seem to rule out a concern about overspeed as an explanation for the PF to make "abrupt and excessive"nose-up control inputs.
At 02:10:55...another of the pitot tubes started working again..."The cockpit's avionics are now all functioning normally. The flight crew has all the information that they need to fly safely, and all the systems are fully functional. The problems that occur from this point forward are entirely due to human error.
Read more: Air France 447 Flight-Data Recorder Transcript - What Really Happened Aboard Air France 447 - Popular Mechanics
"...my question is this...given that the pitot tubes were giving reliable info at this point in the flight...why didn't the flight crew switch the auto-pilot back on?eat
Read more: Air France 447 Flight-Data Recorder Transcript - What Really Happened Aboard Air France 447 - Popular Mechanics
"...my question is this...given that the pitot tubes were giving reliable info at this point in the flight...why didn't the flight crew switch the auto-pilot back on?eat
Another thought...why didn't cockpit protocol dictate that the more senior F/O (Robert) take command/control of the aircraft in the absence of the senior pilot? He seems to have been more aware of the situation!
They also turned on the engine and wing de-icing equipment...why didn't they have the warming equipment for the pitot tubes also activated?
Phil: another thing that may be buried in there but not emphasized about the pitots: It is saying that the tube iced up, BUT, all were Thales tubes that had been recalled for known problems, AND 447 had these tubes and was on the list to have theirs replaced. I wonder if it did actually ice up or just go funky.
Phil,
According to the Flight Crew Operating Manual, pitot heat is automatic when either engine is running or the plane is in flight. According to the report, under very unusual conditions the quantity of ice crystals entering the pitot tube can exceed the de-icing capacity of the heating element.
According to the Flight Crew Operating Manual, pitot heat is automatic when either engine is running or the plane is in flight. According to the report, under very unusual conditions the quantity of ice crystals entering the pitot tube can exceed the de-icing capacity of the heating element.