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View Full Version : Selectioon of incorrect thrust setting on approach


gerard
20th Dec 2004, 20:34
Hi,

Got a query for the pilots out there.

If you were on approach and the FADEC was reset and on power up, instead of the thrust setting being Go-Around, it selected Take-Off - what if anything would you notice and how would it make the plane more difficult to control.

Thanks.

maxalt
21st Dec 2004, 00:18
Several items in that scenario need further elucidation, but to address your main question...if you're talking Airbus, and the a/c is on approach, the difference between TO power and GA power would be negligible or zero.

In fact Airbus name this power setting as TOGA.

Therefore it would not make the plane more difficult to control.

Why would you reset the FADEC on final approach?

gerard
22nd Dec 2004, 13:56
Sorry - I meant a power interrupt.

Do airlines not have the option to request their thrust settings - ie either for performance, relaibility or efficiency.

What is the idea behind the derated options? Are they for weather/runway conditions?

Is there not the possibility that Take-off could be different to Go-Around.

Although they are the same, I think there is the possibility for them to be different.

Thanks.

maxalt
22nd Dec 2004, 23:32
Do airlines not have the option to request their thrust settings - ie either for performance, relaibility or efficiency.Not quite sure what you're getting at here.
What is the idea behind the derated options? Are they for weather/runway conditions?I think you might be referring to FLEXIBLE take off thrust. This is an approved method for reducing Take Off power to save wear and tear on engines.

Derating is slightly more complex and has to do with an engineered permaneant reduction in the available thrust of the engine in all conditions, and the pilot has no control over this reduction.
Sometimes that term DERATE gets misused and confused with the terms "Flexible T/O Thrust" or "Reduced T/O Thrust".Is there not the possibility that Take-off could be different to Go-Around. Although they are the same, I think there is the possibility for them to be different.Again I think you are referring to the FLEX T/O option. In that scenario, yes, there is indeed a difference between the T/O power which you are using and the full T/O power actually available.
But if you need to obtain full power all you have to do is push the thrust levers forward into the TOGA detent on the throttle quadrant.

Does this answer your question?