I was under the impression VMCA on larger jets was also variable due to Cof G Postion. That is to say a more aft Cof G would reduce Rudder authority(or moment) increasing the VMCA.
Flap generally decreases VMCA, because flap increases lift therefore drag, so the live engine wing has more resistance to motion. Or in other words,Flap increases keel surface (under aircraft) increasing resistance to yaw.
Stall Speed changes with C of G postion aswell.
Also with 4 engined jets depending on the failure. If its 1 engine the VMCG and VMCA Speeds are lower than for double assymetric config obviously.
Configeration for VMCA
Max Weight
Least Favourable CG
5degs towards live engine
max thrust on live engine
critical engine failed
prop windmilling or feathered with auto feather
Regards
sheep
p.s. actually found me old ATPL notes
