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View Full Version : Throttle/reverse inter-reaction


BOAC
23rd Jul 2007, 16:45
From the CGH crash thread on R&N it appears that it is possible, on the AB320 anyway, to select TOGA on one engine with a reverser selected open on the other. (NB No suggestion this was the cause!).

I am trying to think of the advantage of this facility and whether it should be blocked? It appears to have certainly caused one accident as per http://www.ntsb.gov/ntsb/brief.asp?ev_id=20020913X01603&key=1

I quote from that:

In an effort at maintaining directional control, the captain then moved the #1 thrust lever out of reverse and inadvertently moved it to the Take-Off/Go-Around (TOGA) position, while leaving the #2 thrust lever in the full reverse position. The thrust asymmetry created by the left engine at TOGA power with the right engine in full reverse greatly increased the right yaw forces, and they were not adequately compensated for by the crew's application of rudder and brake inputs.

Any comments?

bflyer
23rd Jul 2007, 21:31
HI

interresting proposition..question is ..is it feasible for say,three or four-engined aircraft?..and the possible argument from aircraft manufacturers..that the rate of occurence might not justify the additional cost of engineering...that the new set up will have it own set of what might go wrong...mistakes will always happen as long as the human factor is present
And the ready accusation of over-engineering everything.
Now from what i understand that we are looking for a device that will prevent an engine(s) thrust levers from beign advanced if an other engine(s) thrust lever(s) is in the reverse thrust mode..wouldn't this come with its own set of dangers?
Am rambling here..but just my thoughts on the subject for what its worth

BOAC
23rd Jul 2007, 21:38
Well, start with the question - when would you need to do it, and then ask what are the consequences if you do it by mistake? Just a simple mechanical arm which blocks forward thrust selection with the reverser lever out of 'stow' is all that is needed.