What does VMC define when referring to minimum control speed for a light twin-engine airplane?

• A. Maximum speed at which the aircraft can perform aerobatic maneuver.
• B. Minimum control airspeed: minimum flight speed for satisfactory control when an engine becomes inoperative.
• C. Stall speed in the landing configuration.
• D. Best glide speed.

Answer: (B)

VMC is about keeping the airplane controllable when one engine isn’t working. It defines the minimum flight speed at which a light twin can still be steered effectively with the other engine producing takeoff power, so that yaw and directional control remain satisfactory with the critical engine inoperative. In practice, this speed ensures you won’t lose control due to asymmetric thrust if an engine fails during takeoff or initial climb. It’s not about how fast you can drag the airplane through aerobatics, nor about stall speed in a landing configuration, nor about the best glide speed. VMC changes with weight, altitude, and configuration because these factors affect how much rudder and aileron authority you have to counter the unequal thrust.