max q.

About max q

In aerospace engineering, the max q, or maximum dynamic pressure, of an aerospace vehicle's atmospheric flight is the maximum difference between the fluid dynamics total pressure and the ambient static pressure reached by the vehicle. For an airplane, this occurs at the maximum speed at minimum altitude corner of the flight envelope. For a space vehicle launch, this occurs at the crossover point between dynamic pressure increasing with speed and static pressure decreasing with increasing altitude. This is an important design factor of aerospace vehicles, since the aerodynamic structural load on the vehicle is proportional to dynamic pressure.