PPRuNe Forums - View Single Post - AF 447 Thread No. 8
View Single Post
Old 12th June 2012 | 08:23
  #1227 (permalink)  
RetiredF4
15 Anniversary
 
Joined: Jun 2009
Posts: 801
Likes: 74
From: Germany
mm43


@ OK465

It would seem that the major differences in ALT Laws are:-

ALT1:
Pitch attitude (Θ) protection lost.
Hi Speed and Stall speed are alternate.

ALT1A:
As ALT1 but Stall protection is lost.

ALT2:
As ALT1 but lateral normal law is lost and replaced by
lateral alternate (Roll = DIRECT; Yaw = Alternate)

ALT2A:
As ALT2 (Stall protection is lost)

ALT2B:
Pitch attitude (Θ) protection lost.
Hi Speed and Stall protection lost.
Bank angle protection lost

Source - A33Zab in AF447 Thread No.6, and in

ALT2B no Hi and Lo speed stability (= VMO2/ Vc prot),

as explained earlier in this thread.
Thanks for reposting this list.

When BEA and others like Clandestino state, that other UAS events had a positive outcome, can the difference to AF447 partially be found in this list? BEA does not state in which kind of Alternate Law the other events ended, i couldnīt find it at least. So all those events could be just in simple ALT 1, quite a difference to the ALT2B AF447 dropped to.

Last edited by RetiredF4; 12th June 2012 at 09:13.
RetiredF4 is offline