obstruction-clearance speed

obstruction-clearance speed

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The air speed for the steepest angle of climb in a takeoff configuration. Its value is less than the best rate of climb speed, and it is obtained by actual flight tests. It is usually about 1.1 to 1.2 times the basic stalling speed. Also called the obstacle-clearance speed. It should be noted that, since most airplanes climb best with the gear and flaps up, Vx, or the best angle of climb speed, is a clean configuration air speed and is not the speed used to climb over an obstacle during the takeoff climb.