PPRuNe Forums - View Single Post - ATSB report just published on A320 throttle asymmetry incident
Old 26th Jan 2013, 08:17
  #37 (permalink)  
compressor stall
 
Join Date: Feb 2000
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A very interesting event that has two distinct aspects. First is the actions of the PNF in the 80-120kt region, second the actions of the PF in rotating @130kts. I think the actions of the PF were dealt with above.

But IMHO the action that started this incident was the non standard call "Thrust Not Set" when it appears that it was. That lead to the PF's confusion.

To follow on from d_concord's comments:

Immediately after the Thrust Levers are moved into their takeoff detent, MAN FLX 62 (or TOGA etc) appears on the screen. But the engine isn't at the Thrust Set stage yet. It also takes longer for the IAEs to get to power than the CFMs.

The required N1 (CFM) or EPR (IAE) is displayed on the screen just to the right of the engine N1 or EPR. Only when these two are matched can you call "Thrust Set". This is to be done before (not always at) 80 knots.


Now back to this incident: From the little information available, it would appear that the thrust was indeed matched between that commanded by the TLA and that required (it should have exceeded it, but we aren't told this ) . As such the correct call would have been "Thrust Set" even if there was a MAN THR displayed on the FMA. in this case, the FMA has nothing to do with the Thrust required, which is the purpose of the thrust set call.

The correct call (in addition and either before or after the Thrust Set call as noticed) should have been reading the FMA - "Manual Thrust".

Then if was all still going to custard which is the subject of another debate, Go - TOGA was the correct action (as the thrust was indeed set).


Hopefully this thread can remain a healthy discussion here with appropriate respect to the pilots involved about an event from which we all can learn.

Last edited by compressor stall; 26th Jan 2013 at 10:00.
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