In flight mechanics, the “velocity of acceleration” refers to the rate at which an aircraft’s velocity (speed and direction) is changing with respect to time. It is synonymous with the term “acceleration” in the context of aircraft motion.
Acceleration is a vector quantity and is defined as the change in velocity per unit of time. It can be caused by various factors, including changes in engine thrust, changes in aerodynamic forces, and the influence of external forces like gravity or wind.
Va=1.3*Vs
Vs means stalling speed velocity