For Clandestino and PJ2: some bits of old ground that may enhance current discussion.
Some posts Hazelnuts and a few others made germane to handling and stalling at cruise altitude.
http://www.pprune.org/tech-log/45283...ml#post6479432
http://www.pprune.org/tech-log/45283...ml#post6480513
"In level flight at FL350 and M.82 the pitch attitude (=AoA in level flight - HN) was 2.5 degrees".
AoA=4 degrees is approx. the stall warning threshold at M.8 and results in a normal load factor of 1.39.
http://www.pprune.org/tech-log/45283...ml#post6481326 (This is a table of AoA and time in the event)
jcarlosgon
Recovery was done by pushing forward. ... The surprise was how so long it took.
(A comment on control response and time to unstalled a stall jet. )
HN39:
http://www.pprune.org/tech-log/45283...ml#post6485709
At M=0.8 stall warning is set to occur (see 2nd Interim Report) at approx. AoA=4°, alpha-max = 5°, and the real stall is probably between 6° and 7°.
The second stall warning occurred "around 6°" at M=0.68, where alpha-max=7.3° and stall probably beyond 9°.
An intermittent warning such as may occur due to AoA- and hence g-variations due to turbulence may be considered 'inappropriate' since it doesn't require recovery action from the crew, but that doesn't mean it is false.
It means that the AoA has temporarily exceeded the stall warning threshold.
Mieklour
If I can make a small contribution to this thread.
I have flown the A330 in ALT 2 LAW after a twin ADR incident due to icing conditions.
What surprised me was how "twitchy" the aircraft was, especially in roll.
The handling was much harder than I had experienced in the simulator during training.
We however continued to have valid ADI indications with which to fly attitude + power whilst trying to sort out the very numerous ECAM warnings plus alternating "Stall, stall" + overspeed warnings (spurious of course)
Why the crew should have applied pitch up inputs is a mystery to me unless it was a response to a perceived large overspeed but then why leave the power up?
As mentioned by other posters - the need to manually trim the THS forward is an area that is often seen to be missed by crew undertaking unusual attitude recovery training, especially from very high nose up attitudes and is, in my opinion, one of the few `real gotchas` about the aeroplane.
http://www.pprune.org/tech-log/45283...ml#post6486989
It certainly was investigated! Aug 1995 and resulted in the fitting of pitot heads with increased heating and a software change to increase the time line before ALT2 was latched. A/P and ATHR initially lost but were restored once out of icing conditions however the lateral twitchy aileron response was very evident for the landing.
http://www.pprune.org/tech-log/45283...ml#post6487728
Here is the picture that I think will help, courtesy of Hazel Nuts.
https://docs.google.com/leaf?id=0B0C...thkey=CILGt_QN
BBF has a chilling summary. It may be hyperbole, given Mieklour's experience with flying it back in Alt 2 latched from cruise altitude. :
Straight and level was beyond them. So used were they to the automatics that the concept of actually flying the aircraft was too much.
Autos- and the way they degrade those hard earned flying skills- are the new killer.