Definition
Position or status reports that a pilot is required to make to ATC without a specific request, in addition to the routine reports already required by regulation or clearance. They cover events such as a change in true airspeed, vacating an assigned altitude, an inability to climb or descend at 500 feet per minute, missed approaches, loss of navigation capability, weather encounters, and similar conditions that affect the safe or expected progress of the flight.
Plain English
These are extra reports a pilot must give to air traffic control on their own initiative, without being asked, whenever certain things happen during the flight that controllers need to know about.
Context Anchor
Seen in instrument flight position-report procedures, especially when flying under air traffic control between normal reporting points.
Why Pilots Care
These reports keep controllers aware of your exact flight status so they can maintain safe separation from other traffic.
Intuition Check
Additional does not mean optional here. It means reports made in addition to normal position reports when the rules or the situation call for them.
Example Sentence 1
When the aircraft could no longer maintain a 500 feet per minute climb, the pilot made an additional report to Center as required.
Example Sentence 2
After the standard position report at the VOR, the pilot made an additional report when reaching the next compulsory fix.