Custer Channel Wings for Short Takeoff and Landing of Unmanned Aircraft

The channel wing is a lift-enhancement concept pioneered by Willard Ray Custer in the late 1940s in an effort to provide a fixed-wing aircraft with short takeoff and landing (STOL) capabilities. This paper experimentally investigates the possibility of using Custer channel wings for slow flight and STOL of small (under 35 kg) fixed-wing unmanned aerial vehicles. The Custer unmanned aircraft developed at the University of Southampton is introduced in this paper, including details of the installed channel wings and other systems necessary for slow-flight operation. Results from wind-tunnel tests are presented, showing a significant lift increase due to the channel wings in the range of airspeeds of interest. Flight tests are carried out to demonstrate the slow flight and STOL capabilities of the aircraft, showing superior stall characteristics and a two-thirds reduction of the runway length required when using the channel wings. Flight-test comparisons to a conventional wing–propeller configuration show superior slow-flight performance and 7–9% lower cruise speed of the channel-wing aircraft.