Morphing wings are of great interest in the aerospace community. Control surfaces with continuously variable geometry can increase the efficiency of aircraft aerodynamics. This research focuses on demonstrating a morphing flap on a small span-wise section of the trailing edge in a wing for a small unmanned air vehicle (UAV). The flaps used flexible matrix composite (FMC) actuators embedded in a flexible structure, rather than hinged control surfaces with conventional actuators. This created a local aerodynamic control force whose effect can be measured using the UAV’s on-board flight control system. After multiple design iterations, in which the FMC actuator material and structure were varied, the final design incorporates a carbon fiber frame with an actuator system embedded in a foam matrix. The FMC control surfaces were successfully demonstrated in flight tests on the eSPAARO unmanned aerial vehicle.