posted on May, 27 2011 @ 05:40 PM
On the note about the pitot tubes.
Yes units where fitted that were known to have an issue with the heating element, insufficient to protect them against ice build up. There was
maintenance action in progress in the fleet to resolve this. This was not donw on this aircraft. However this alone should not have brought the plane
down. correct application of thrust and attitude will stabilize the aircraft sufficiently so they have time to figure the issue out. however this is a
contributory probable cause, and not yet fact.
ON the report itself this is a sort of translation as best can
020146 - Pilot have hand over brief with co pilots informs cabin crew about turbulence and leaves the cockpit to go to crew rest. - this is normal.
FL350 (35000 ft) M0.82
020807 - turns left 12 degrees from planned course (probably to avoid a reallt nasty area)
021005 - Autopilot and auto-thottle disengage - this happens when the rock and roll is too bad, and the plane says. Over to you chum. hard right turn
and nose up. speed indication drops from 270kts to 60kts (icing on pitot???) or wind buffeting. the plane gives off a stall warning. twice.
021016 - Pilot declares alternate law due to "lost speeds" this means that the aircraft is not operating normally and they have reduced protections.
note this is NOT reduced control. just system protection. the plane pitches up to above 10 degrees nose up, and starts to climb, rolling left to
right. then indicated speed increases to 215kts at 4 degrees nose up, with verticle speed at 700 fpm (reduced from 7000 fpm)
(this is why I question the iced pitot theory, why would the IAS go and then come back if it was blocked?)
021050 - PF calls the Captain.
021051 - Stall warning and pilot engages TOGA (Take off Go Around) this is PULL POWER with 6 degrees nose up and increasing. The THS (Trimmable
Horizontal Stabilizer( the to small wings at the back)) move from 3 to 13 degrees nose up. meaning they are pointing down 13 degrees.
there is a part missing here
021106 - speed INCREASES to 185 kts (it was 215kts at 021016, so what happened to the speed at 021051?) PF continues nose up inputs on the control
stick (why?) with nose up at 16 Degrees.
021140 - Captain enters the cockpit - a few seconds later all air speeds become invalid (meaning reading less than 60kts and angle of attack is
ignored by the system) (icing here??) but for speed values to be invalid they have to be reading less than 30kts.
The aircraft is now at FL350 (35000) with angle of attack in excess of 40 degrees with vertical speed at -10000 fpm. (near free fall speed) pitch was
not more than 15 degrees. meaning he is well outside the flight envelope.again oscillating left and right up to 40 degrees each way.
021202 PF and PNF declare that reading are invalid. AT this point the thrust is set to IDLE!
This is what makes me believe that he though he was diving. high vertical speed down, and constan nose up inputs. setting the thrust to idle, to help
slow him down, or at least not get any faster. Possible reason, he was worried about going "over-speed" a common worry when you don't really know
how fast you are. as you might tear off the wings.
At this time, he pushed the nose down, speed increased and readings became valid again. But because the speed being invalid had caused the stall
warning to stop, once it became invalid the stall warning started again!
021332 a pilot noted that they were about to reach 10000 ft. both control stick move in the same direction and the PF said "go ahead you have the
controls"
This is consistent with the procedure in Airbus to transfer priority control from one stick to another. IN this case I believe Priority left. meaning,
I think, the Captain was back in the seat, and taking control.
angle of attack, when valid, remained above 35 degrees. if the pitch never went above 15 degrees then never made it out of the deep stall, or even
came close to it.
recording stops at 021428.They hit the water at 10900 fpm vertical speed. slight nose up and slight roll to one side.
On a personal note, people will assume and call this pilot error, in fact they are already starting. However this situation is not the first time,
spacial disorientation, which is probable in this case, has occurred. Not knowing for sure what your plane is doing, and with blackness out of the
windows, you have no real point of reference. Coupled with the feeling that you can't trust your instruments, and you body telling you one thing is
happening, when something entirely different is happening. it is a nightmare scenario. Not their fault at all. And I feel deeply for them, in what
they had to try and deal with. May this never happen again.