What is the maneuvering speed used for categorizing aircraft?

Maneuvering speed, often denoted as Va, is an important flight parameter that represents the maximum speed at which an aircraft can be safely controlled in turbulent air. It is defined as the speed below which full deflection of the control surfaces can be achieved without risking structural damage to the aircraft.

The correct choice, which is 1.3 times VSO (the stall speed in a specified configuration), is significant because it provides a buffer of airspeed above the stall speed in level flight. This means that at this speed, pilots can apply significant control inputs and experience full maneuverability without entering a stall. Therefore, operating at this speed ensures that the aircraft remains within a safe margin during maneuvers, especially in turbulent conditions.

While the other values of VSO multiplied by 1.1, 1.5, or 2.0 could have other implications in specific contexts, they do not accurately represent the standard maneuvering speed category used in general aviation, making 1.3 x VSO the most universally accepted figure for maintaining safe operational control during maneuvers.