The Transformer aircraft: a multimission unmanned aerial vehicle capable of symmetric and asymmetric span morphing

This paper presents the development and extensive testing of the Transformer aircraft, a multimission UAV capable of symmetric and asymmetric span morphing. The UAV utilises a novel actuation system based on a rack and pinion mechanism to achieve span extensions up to 50%. The Transformer can morph symmetrically to enhance flight performance and asymmetrically to provide roll control. Extensive mechanical testing followed by wind-tunnel testing in the RJ Mitchell Wind-tunnel at the University of Southampton were conducted to ensure structural integrity and assess the behaviour of the UAV. Finally, a series of flight-testing were performed and the flight mechanics aspects associated with both symmetric and asymmetric span morphing were investigated.