Definition

A Flight Control Unit (FCU) is part of the system architecture for automatic flight functions of certain aircraft. The phrase is most commonly associated with Airbus models. An FCU performs functions similar to the Guidance Panel (GP) on Embraer aircraft.

Description

The FCU controls and indicators are located on the glareshield panel. The FCU allows a pilot to make selections for airspeed and altitude, for lateral navigation modes, and for autothrust activation. The FCU also allows pilots to select various vertical modes, such as a climb or descent based on vertical speed per minute, or based on climbing or descending at a selected airspeed.

Other Airbus FCU functions include a SPD/MACH button, which allows selection between speeds indicated in Mach or in knots. A LOC button arms or disarms localizer capture. An APPR arms and disarms instrument landing system (ILS) approaches, and a METRIC ALT button allows altitude display in meters. An EXPED button underneath the altitude selector allows for an expedited climb. The vertical speed knob includes a push-to-level off function.

The Airbus autopilot works in two different modes: Managed mode means flight parameters are set through the Multifunction Control and Display Unit (MCDU). Selected mode means flight parameters are set directly on the FCU.