Stall speed in a landing configuration is denoted by which symbol?

• A. Vs1
• B. Vs0
• C. Vne
• D. Vfe

Answer: (B)

Stall speed is the minimum airspeed at which the wing can support the airplane in a given configuration; below this speed the wing can no longer produce enough lift to maintain level flight. In the landing configuration, with flaps extended and gear down, the lift characteristics change, allowing the airplane to fly safely at a lower speed than in clean (flaps up) configuration. The symbol used to denote stall speed in that specific landing setup is Vs0, where the subscript zero indicates the landing configuration.

So Vs0 is the stall speed for the airplane with flaps down and gear down. (For comparison, other subscripts refer to different configurations, such as takeoff or clean configurations, while Vne and Vfe denote other limits like never-exceed speed and maximum flap-extended speed.)