PPRuNe Forums - View Single Post - AF447 final crew conversation - Thread No. 1
Old 24th Jan 2012, 12:24
  #1138 (permalink)  
infrequentflyer789
 
Join Date: Jan 2008
Location: uk
Posts: 818
Originally Posted by BOAC View Post
I quite agree, Mac - placing that in front of our 447 crew would, I think, have merely hastened their demise (if that was possible)
they would probably never have seen the display since ( I believe) they would have had to select all ADRs off to get it, following a procedure - and they never even started any procedures.

However, by side-effect, BUSS might have saved them - if you believe off/on SW killed them, read on...

HN39 - if I read you correctly there, the BUSS is 'deducing' AoA from inertial GS/FPA and attitude?
No, what it says is that the BUSS options routes AoA sensor data (raw, I guess) through the IR side (as well). BUSS can then use that AoA data, maybe in conjunction with inertials, even when the airdata side is shot (or off).

Now, the interesting thing is the stall warning comment - which says to me that as well as feeding the BUSS, the re-routed AoA signal from the new ADIRU also feeds the SW logic. Which, I think, means that SW would be continuous even if airdata calculations invalidate AoA data on that side of the ADIRU, and that would apply whether the BUSS is engaged (ADRs off) or not.

Not saying BUSS would have helped, but if anyone's thinking that BUSS wouldn't have helped because it's useless above FL26 etc. and that the on/off SW was the killer... then they might want to reconsider.
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