Which condition increases VMC?

Which condition increases VMC?

• A. Power reduction on the operating engine.
• B. Increased altitude.
• C. Aging engine.
• D. Max power on the operating engine.

Answer: (D)

VMC is the speed at which you can still control the airplane with one engine out, determined by the yawing moment created by asymmetric thrust and the rudder’s ability to counter it. The bigger the thrust of the operating engine relative to the failed engine, the stronger that yaw tendency, and the higher the speed you need to stay in control. Pushing the operating engine to maximum power increases that yaw moment, so VMC rises. Reducing power on the operating engine lowers the yaw moment and lowers VMC. Increasing altitude tends to raise VMC because rudder effectiveness decreases in thinner air, but the most direct factor among the options is maximizing the operating engine’s power, which directly amplifies the yawing moment. Aging the engine usually reduces thrust, which would not increase VMC and can even lower it depending on conditions.

VMC is the speed at which you can still control the airplane with one engine out, determined by the yawing moment created by asymmetric thrust and the rudder’s ability to counter it. The bigger the thrust of the operating engine relative to the failed engine, the stronger that yaw tendency, and the higher the speed you need to stay in control. Pushing the operating engine to maximum power increases that yaw moment, so VMC rises. Reducing power on the operating engine lowers the yaw moment and lowers VMC. Increasing altitude tends to raise VMC because rudder effectiveness decreases in thinner air, but the most direct factor among the options is maximizing the operating engine’s power, which directly amplifies the yawing moment. Aging the engine usually reduces thrust, which would not increase VMC and can even lower it depending on conditions.