Full-scale wind-tunnel investigation of the aerodynamic characteristics of the X-24A lifting body aircraft

The aerodynamic characteristics of the X-24A aircraft were investigated in the Ames 40-by 80-Foot Wind Tunnel.The aircraft was tested over an angle-of-attack range of-4 ° to +32 °, an angle-of-sideslip range of -6 ° to +6 °, for several longitudinal, lateral, and directional control settings, and for Reynolds numbers ranging from 20.7×106 to 41.6× 106 .(Most of the data were obtained at a Reynolds number of 32.4× 106.) Results were obtained with the landing gear both up and down.With the landing gear up the maximum lift-to-drag ratio achieved was 5.2 untrimmed and 4.4 trimmed.With the landing gear down the maximum trimmed L/D was lower by an amount which varied from 0.8 to 1.8, depending oll the upper flap deflection.In flight, lowering the landing gear would require a longitudinal control change of 7° to 10 °, depending on the angle of attack, to maintain a constant lift coefficient or forward velocity.A limited comparison with 1/5 scale-model longitudinal results showed very good agreement.