In flight performance terminology, what does Vmc represent?

In flight performance terminology, what does Vmc represent?

• A. Minimum Control Speed With Critical Engine Inoperative
• B. Maximum Control Speed With Critical Engine Inoperative
• C. Minimum Velocity With One Engine Operating
• D. Normal Operating Speed With One Engine Inoperative

Answer: (A)

Vmc is the minimum speed at which the airplane can be kept under directional control with the critical engine inoperative. When an engine fails on a twin, thrust asymmetry tends to yaw the aircraft toward the failed side, and you rely on rudder and a bit of bank to counter that yaw. As speed decreases, rudder effectiveness and control authority drop, so below Vmc you may not be able to maintain straight flight with the remaining engine at takeoff power. This speed is defined under specific test conditions to ensure the airplane remains controllable in a worst‑case scenario. The other descriptions refer to different, unrelated speeds and don’t describe the controllability with one engine inoperative.

Vmc is the minimum speed at which the airplane can be kept under directional control with the critical engine inoperative. When an engine fails on a twin, thrust asymmetry tends to yaw the aircraft toward the failed side, and you rely on rudder and a bit of bank to counter that yaw. As speed decreases, rudder effectiveness and control authority drop, so below Vmc you may not be able to maintain straight flight with the remaining engine at takeoff power. This speed is defined under specific test conditions to ensure the airplane remains controllable in a worst‑case scenario. The other descriptions refer to different, unrelated speeds and don’t describe the controllability with one engine inoperative.