PPRuNe Forums - View Single Post - AF 447 Thread no. 4
View Single Post
Old 2nd Jul 2011, 11:08
  #638 (permalink)  
Chris Scott
 
Join Date: Jan 2008
Location: Blighty (Nth. Downs)
Age: 77
Posts: 2,107
Received 4 Likes on 4 Posts
Quote from BOAC:
JC makes a very valid point in #624 - is 'flying by hand' actually what happens or is there still something 'interfering' and thinking it knows better?

That is why Dozy Wanabee and I are suggesting that, in the UAS case, the reversion should be all the way to Pitch-Direct, requiring the PF to do the pitch-trimming. This stick-to-elevator mode does impose limits on full-travel, according to the aircraft CG (comparable to the rudder-travel limiter, which limits as a function of airspeed). Other than that, there is no interference from the FBW computers.

Early A320s are, in certain failure modes, unable to maintain Pitch-Alternate Law once the gear is extended (due to potential stall of the emergency RAT from turbulent airflow behind the nose leg). The crew knows that they will have to fly the last part of the approach in Pitch-Direct. The handling characteristics do change, and forewarned is forearmed. So, returning to the UAS case, I'm also suggesting a slight pause in Pitch-Alternate, but am all ears for the counter-arguments.
Chris Scott is offline