How is VMCA influenced by increasing pressure altitude?
A. VMCA decreases with increasing pressure altitude B. VMCA increases with pressure altitude higher than 4000 ft C. VMCA increases with increasing pressure altitude D. VMCA is not affected by pressure altitude
The correct answer to this question is A. Velocity - Minimum Control (air) is more commonly referred to as Vmca. Vmca is the minimum control speed below which directional or lateral control of the aircraft can no longer be maintained after one more engines fail. Vmca only applies if at least one engine on the aircraft is still functioning.
An aircraft with a higher altitude has a lower force of the operative engine, less counteractive force for the rudder, and decreased Vmca. Many other factors also affect Vmca, such as take-off flaps and take-off power at sea level.
Noop it decreases as your thrust decreases with the pressure altitude..u need less aerodynamic force around the rudder to control the yaw... so VMCA decreases, it only increases with higher density altitude.