12 SHOCK ABSORBERS AND LANDING GEARS FOR AIRCRAFT; AIRCRAFT HYDRAULIC STEERING SYSTEM COMPONENTS-NAMELY, VALVES, LINEAR AND ROTARY MECHANICAL ACTUATORS AND MECHANICAL AND ELECTRO-MECHANICAL SERVO-MECHANISMS; AIRCRAFT COMPONENTS, NAMELY HYDRAULIC SERVO FLIGHT CONTROLS COMPRISED OF VALVES, ACTUATORS AND HYDRAULIC, MECHANICAL AND ELECTRO-MECHANICAL FEEDBACK MECHANISMS FOR AILERONS, SPOILERS, RUDDERS, LEADING EDGE SLATS AND FLAPS AND CANARDS SURFACES, AND PARTS THEREFOR