Future Air Navigation System
![The datalink control and display unit (DCDU) on an Airbus A330, the pilot interface for sending and receiving CPDLC messages.](/Images/godic/202501/14/A330_DCDU5550.jpg")
The Future Air Navigation System (FANS) is an avionics system which provides direct data link communication between the pilot and the air traffic controller. The communications include air traffic control clearances, pilot requests and position reporting. In the FANS-B equipped Airbus A320 family aircraft, an Air Traffic Services Unit (ATSU) and a VHF Data Link radio (VDR3) in the avionics rack and two data link control and display units (DCDUs) in the cockpit enable the flight crew to read and answer the controller–pilot data link communications (CPDLC) messages received from the ground.