Design of Flight Control System Mechanism for National Glider GL-1

This paper reports a design of flight control system mechanism which will be implemented in the national glider GL-1. The flight control system in the glider GL-1 includes the following control surfaces: elevator, ailerons, and rudder for primary flight control system as well as flaps and airbrakes for secondary one. In designing the components of flight control system, selections of type, material, and dimension of components are based on loads computation as well as benchmarking to some modern gliders. Mechanism and kinematics of flight control system are designed to comply with regulation as well as space availability. Fully-mechanical flight control system is selected for the aircraft since the aerodynamic forces acting on the glider are not excessive. The aircraft uses a centre-stick as manipulator for pilot to control longitudinal and lateral movements, which is linked to elevator and ailerons by push-pull rods with coupled mechanism. Meanwhile, for directional control, an adjustable pedal is used. The pedal is linked to the rudder by tension cables. Plain flaps and flat-plat panel airbrakes are selected as flap and airbrake types in this glider. The flaps and airbrakes are controlled by mechanical levers, which are linked by push-pull rods.