LL
An interruption or loss of the control link, or when the pilot is unable to effect control of the aircraft and, as a result, the UA will perform a predictable or planned maneuver. There are two types of links: an uplink which transmits command instructions to the aircraft, and a downlink which transmits the status of the aircraft and provides situational awareness to the pilot.
Source FAA Pilot/Controller Glossary · checked 2026-08-25