Plain English Meaning

The speed that gives a twin-engine airplane its best climb when one engine has quit and the other is doing all the work. Flown correctly, it gets the airplane up as fast as possible with the power available.

Full Definition

In a multi-engine airplane, the airspeed that produces the greatest gain in altitude per unit of time when one engine is inoperative and the remaining engine is producing takeoff or maximum continuous power. VYSE is published by the manufacturer in the Airplane Flight Manual and is marked on the airspeed indicator with a blue radial line, commonly called the 'blue line.'

Context Anchor

You will see VYSE in multiengine training, , , and on the airspeed indicator as the blue line.