INVESTIGATION AT ZERO FORWARD SPEED OF A LEADING-EDGE SLAT AS A LONGITUDINAL CONTROL DEVICE FORnVERTICALLY RISING AIRPLANES THAT UTILIZE THE REDIRECTED-SUPSTREAM PRINCIPLE

摘要

An investigation of a leading-edge slat as a possible longitudinal control device for vertically rising airplanes that utilize the redirected slipstream principle has been conducted at zero forward speed in a static thrust facility at the Langley Aeronautical Laboratory A semispan wing model equipped with large-chord slotted flaps and two large-diameter over lapping propellers was used in the investigation.nThe results indicate that a leading-edge slat can provide increments of pitching moment of the order of those required for control and change in trim with center-of-gravity travel for a vertically rising airplane in hovering flight. In the ground-effect region, however, the slat is generally ineffective as a longitudinal control device. Slat positions above the wing chord plane are preferable to positions below the wing chord plane. The slat also achieved an appreciable reduction in the adverse effect of the ground on the effectiveness of the slotted-flap wing configuration in redirecting propeller slipstreams downward.