While we are at speculating:
(Attention: This is all really speculation and I'm impatiently awaiting the results of the FDR /CVR analysis after they will be hopefully found soon). Will be interesting to see in hindsight where the brain farts were.
So for what it's worth:
Here comes my scenario which I have in mind based on what we know atm :
2:09:30
Being in Cb with supercooled droplets. Pitots starting to freeze over.
2:10:00 - 2:10:15
Pitot fail, unreliable airspeed.
AP A/THR disconnect.
Possibly showing overspeed causing the Pilots to reduce Thrust, leading to slow decelleration
ADR disagree, Alternate Law 2
Edit: Following comment by @Sensor_validation I agree AP /A/THR deactivation and switch to Alt2 probably occured more or less simultaneously, time delay in ACRAS only due to ACARS transmission
/Edit
2:10:15 - ~2:11:00
Pilots manually trying to keep the plane straight and level, significant turbulence being countered by significant control inputs, not being covered by protections.
Meanwhile:
2:10:34 Last position report transmitted, already in Alt 2 3nm left off course possibly indicating pilots already fighting the situation.
Probably shortly after reporting of LKP:
Manual overcontrol in pitch combined with reduced speed and strong vertical gusts leading to accelerated stall causing massive wing drop. Causing loss of spatial orientation due to severly moving Attitude indication.
2:11:30 - 2:14:30 Aircraft progressively stalled.
Heavy loss of forward velocity, decellerating from ~250kts CAS to <100 kts. Potential course reversal after initial wing drop. Pilots regaining horizontal attitude.
Heavy loss of altitude, RoD ~ 20000 ft/min. 'Falling Leaf attitude'. possiibly combined with slow rotation or erroneous heading change while dropping. In between partly recovery possible. Re-activation of AP possible while Airspeed still unreliable but consistent. Potentially followed by subsequent stall(s).
In denser atmosphere RoD decreasing to 15000 ft/min. Forward speed reduced to < 100kts.
2:14:30 - 2:15:15.
Edit:
Following Comment by @Sensor_validation I tend to agree time of crash seems more likely towards 2:14:30
/Edit
Impact on the surface: Vertical speed : 150kts, horizontal speed: 50 - 100 kts. Pitch angle: 20 - 30° Nose up, perhaps slightly less. Engines at high N1/EPR. (Does that match the pictures of the engine ?)
Heading at impact: between 090 and 180.
Is there any obvious thing which I oversaw which contradicts this sequence? Are there any obvious brain farts identifiable already now ?
Any comments ?
Please feel free to challenge/dissect it part by part.
Last edited by Jetdriver; 18th April 2011 at 16:00.