flightcontrolunits

A flight control unit, abbreviated FCU or Flight Controller, is the central computing element in an aircraft that processes sensor data and commands actuation systems to control flight. In unmanned aerial vehicles, the term is commonly used to describe the on-board computer that stabilizes the aircraft and executes flight plans. In manned aircraft, the Flight Control Unit can refer to the autopilot control system integrated with the cockpit's control panel, enabling automatic handling of certain flight tasks.

The FCU integrates multiple inputs and outputs. On the input side it collects data from inertial measurement units (accelerometers and gyroscopes), barometers, magnetometers, GNSS receivers, and air data sensors. It maintains a state estimate for position, attitude, altitude, and velocity. On the output side it drives actuators or servo systems through interfaces such as PWM, CAN, I2C, SPI, or power electronics to control motors, control surfaces, or hydraulic actuators. The unit typically also manages power distribution, fault detection, and software that governs mission logic or flight modes.

Software and firmware running on FCUs vary by platform. Popular firmware stacks in the hobbyist and research communities include PX4, ArduPilot, Betaflight, and iNav. These systems implement stabilization, position hold, altitude control, waypoint navigation, and custom mission scripting, with sensor fusion algorithms to produce reliable state estimates. In certified aviation, FCUs are subject to stringent safety and reliability standards and often include redundancy and rigorous testing.

See also: flight controller, autopilot, unmanned aerial vehicle, sensor fusion.