The concept you are looking for is that there is less asymmetry
when you are higher in altitude.

Unless it's a turbocharged aircraft.

For 20 extra points, if you can get full sea level manifold pressure
in a TC
airplane, does Vmc decrease with an increase in altitude?

Bill Hale

On Aug 4, 2:47*pm, Michael Huber wrote:
gatt wrote:
2) *How is VMC affected by an increase in altitude?
b) VMC goes down.

Less thrust, although this still confuses me somewhat in terms of
indicated airspeed.

As I understand it, it's the following: The airplane's behavior is only
dependent on indicated airspeed, as that reflects the forces the air exerts
on the plane. So, at any given _indicated_ airspeed, the forces the rudder
is able to generate are the same. However, the forces the engines are able
to generate decrease with altitude. Thus, VMC indicated is going to be less
the higher you are.