Denti,
I agree with the requirement NOT to increase thrust to the full rate thrust following an engine failure during/after a derate T/0.
If you fly at full rated thrust,aft CG,light weight,and you DONT bank into the good engine,your actual Vmca will increase,with the possibility of your actual speed being below the set VMCA for your engine thrust setting.(derate or not).Derate gives a lower VMCA.
The problem comes when engine failure turn require to bank 15 at V2 due to obstacles (worse scenario left turn with a left engine failure).Problem being increased by the spoiler assist design during turns.
When flying at VMCA(aircraft cant maintain the heading), Reducing the thrust on the good engine, isnt a way to recover the aircraft control by reducing the assymetrical force?(if rudder and ailerons are not effective
enough during take off?).
From Avioconsult:
'The actual VMCA can also be lower – safer – than the AFM published VMCA though, for instance when the asymmetrical thrust is not as high as used during VMCA testing or the cg is forward. VMCA can also be lower than stall speed VS in which case the airplane is said to be controllable down to the stall, which however does not apply for all bank angles.'
Last edited by de facto; 27th May 2010 at 13:52.