Plain English Meaning
The parts that translate the pilot's movements of the yoke, stick, rudder pedals, and trim into actual movement of the surfaces on the wings and tail that steer the aircraft.
Full Definition
The mechanical, hydraulic, electrical, or fly-by-wire arrangements that connect a pilot's cockpit inputs to the aerodynamic surfaces and devices that control an aircraft's attitude, flight path, and aerodynamic configuration. Primary flight controls (ailerons, elevator or , and ) govern , , and . (such as , , , and ) refine or the aircraft's handling, , and characteristics.