The flying controls of the Sea Vixen were relatively complex, which controlled the fully powered tailplane, ailerons, and rudder; these controls remained usable even in the absence of electrical power, such as in the event of a double engine failure. Actuation of the powered flight control surfaces was provided by a pair of independent hydraulic systems and typically featured variable gearing of control movements over differing speeds. An intricate three-section flap arrangement was employed, partially due to the nature of the wing's geometry. The navigation, flight instrumentation and communications equipment included ground and air position indicators, a reference gyro, an autopilot capable of maintaining altitude and speed as well as yaw and pitch damping, tactical air navigation system (TACAN), and ultra high frequency (UHF) radio system.