A gurney flap assembly (50) has an actuator (100), a flexible or hinged body (155), the body flexing from a retracted to a deployed position in reaction to motion of the actuator, and a first seal (162) extending along a first edge of the flexible body (155). that flexes from Linear motion of the actuator output (100) is transposed to the gurney flap (155) thereby moving it from a retracted position into the airstream. This trailing edge device will improve airfoil lift.