PPRuNe Forums - View Single Post - Habsheim
Thread: Habsheim
View Single Post
Old 24th Feb 2014, 02:50
  #546 (permalink)  
CONF iture
Join Date: Jan 2005
Location: W of 30W
Posts: 1,939
Originally Posted by awblain
At Bilbao, if the aircraft is being pitched around so that it enters a protection mode, then it's possible that at least briefly it needed protection - not smoothing the flight path, but avoiding stall. This might have caused it to impact the ground, but what if it had been allowed to stall and crash instead?
Don't panic with the stall scenario, at 10 deg of AoA they were just not there yet.
And if you think 4.5 G is not a ground impact, then what is an impact ... ?
Lack of pitch authority in short final was the problem.

Originally Posted by Owain Glyndwr
Seeing the steady loss of airspeed during the last few seconds this term led to a nosedown signal which offset the pilot's command for more AOA and restricted the aircraft to 15 deg AOA rather than the 17.5 deg of alphamax.
I have nothing against you wanting to state why alpha max was refused in Habsheim, but don't you think that was a task and duty for the BEA to endorse in the first place ... ?
That being said :
  1. 1kt/sec deceleration is nothing extraordinary and is precisely the deceleration rate recommended to adopt for testing the protections or voluntarily approaching the stall. The nose down signal in Bilbao was triggered by loosing 13kt for a 2 sec period.
  2. Last second of speed data shows already an acceleration.
  3. Engines were at 83%N1.
Everything was in place to benefit from the widely advertised wonder of alpha max and not simply straight fully fly into the forest.
CONF iture is offline