Parafoil Control Authority with Upper-Surface Canopy Spoilers

Abstract

Current autonomous parafoil and payload aircraft are controlled by deflection of the canopy trailing edge. Asymmetric trailing edge deflection results in a turn, symmetric deflection results in a change in speed with little change in glide slope. The inability to control glide slopewith these traditional canopy controlmechanisms is severely detrimental to the landing accuracy of parafoil and payload aircraft, especially when turbulent atmospheric conditions or difficult terrain are present near the landing area. An alternative canopy control mechanism is investigated where internal air is vented through the upper surface of the canopy to create an aerodynamic spoiler. Flight-test results for various configurations of the spoiler concept are presented. It is shown that a dramatic change in glide slope can be generatedwith relatively small spoiler actuations. Furthermore, it is shown that the same lateral control authority availablewith trailing edge brakes can be achievedwith asymmetric actuation of the upper-surface spoilers.