The term Vmc relates to flight performance with an engine inoperative; it is defined as

The term Vmc relates to flight performance with an engine inoperative; it is defined as

• A. The maximum speed with the engine operable
• B. The minimum speed for safe engine-out turns
• C. The minimum control speed with the critical engine inoperative
• D. The stall speed with one engine inoperative

Answer: (C)

Vmc is the minimum speed at which you can still control the airplane with the critical engine inoperative. When an engine fails on a multiengine aircraft, the remaining thrust creates yaw toward the failed side. If you’re flying slower than Vmc, the rudder and other controls aren’t effective enough to counter that yaw, so you can’t maintain coordinated, straight flight. At or above Vmc, with the operative engine at takeoff power and using the aircraft’s aerodynamic controls, you can keep the airplane controllable and recover from the asymmetrical thrust. This value isn’t about maximum speed with the engine operating, it’s not the minimum speed for engine-out turns, and it’s not the stall speed; it specifically defines the controllable speed with one engine inoperative.

Vmc is the minimum speed at which you can still control the airplane with the critical engine inoperative. When an engine fails on a multiengine aircraft, the remaining thrust creates yaw toward the failed side. If you’re flying slower than Vmc, the rudder and other controls aren’t effective enough to counter that yaw, so you can’t maintain coordinated, straight flight. At or above Vmc, with the operative engine at takeoff power and using the aircraft’s aerodynamic controls, you can keep the airplane controllable and recover from the asymmetrical thrust. This value isn’t about maximum speed with the engine operating, it’s not the minimum speed for engine-out turns, and it’s not the stall speed; it specifically defines the controllable speed with one engine inoperative.