REDUCTION OF TILTROTOR DOWNLOAD

Devices which reduce tiltrotor download were developed using small sca le testing and substantiated through full scale flight testing,. The s mall scale tests were conducted using a semi-span model consisting of a rotor, wing, fuselage, and image plane, Full scale evaluation of dow nload reduction devices derived from model testing was conducted on th e XV-15 resulting in significant increases in hover lift capability be tween 2.5% and 3.5%, Encouraged by full scale results, follow-on small scale testing was conducted which included testing of devices, flow v isualization, and flow measurements to gain insight into the mechanism responsible for the increased lift, This paper demonstrates the effec tiveness of model scale testing to guide full scale design.