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M.82
27th Dec 2011, 21:13
Hi guys,

Sory but I was reading my FCTM again and I cannot understad the relationship between the N1 value that you get from a Reduced Thrust (ATM or Fixed Derate) Take OFF, and the VMCG and VMCA.

How can VMCA and VMCG change with N1?
:ok:
Thanks!

STBYRUD
27th Dec 2011, 22:00
More thrust to start with -> more asymmetric thrust during an engine failure that would have to be countered with the flight controls, reducing the takeoff thrust will lower minimum control speeds as well.

mutt
28th Dec 2011, 06:33
Go back and read the manual again, it should tell you that YOUR VMCG/VMCA doesn't change with reduce thrust using the ATM method.

Mutt

STBYRUD
28th Dec 2011, 07:03
Only because the performance calculations always assume fully rated thrust or fixed derate, true...

M.82
28th Dec 2011, 13:30
Yes, sure, VMCG and VMCA are modified if you take off with a Fixed derate.

Thanks STBYRUD, it's true, "more power = more asymmetri"

Thanks guys
Happy new year