Lost Link (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. Loss of command and control link between the Control Station and the aircraft. 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.