Definition
An aircraft departure that has taken off from an airport but has not yet been radar-identified or contacted by the appropriate Air Route Traffic Control Center (ARTCC). It is a status label used by ATC to track recently departed aircraft during the brief window between liftoff and positive radar identification.
Plain English
A plane that has just taken off but hasn't yet been picked up on radar or made contact with the en route controllers. It's a short, in-between status used by air traffic control.
Context Anchor
You may see this term in air traffic control instructions, airport traffic discussions, runway sequencing, and traffic flow planning.
Derivation
The 'A' stands for 'Active' in ATC shorthand — an aircraft that is active in the system as a departure but not yet fully handed off and identified by the next controlling facility.
Why Pilots Care
Knowing this term helps pilots understand why there's sometimes a brief delay or specific phraseology when transitioning from tower to departure or center frequencies. It's a reminder that radar identification is a distinct event from takeoff itself.
Intuition Check
Do not read departure only as a scheduled airline time. In this context, a departure is the aircraft or flight leaving the airport.
Example Sentence 1
The tower coordinated with the center on an A Departure climbing out of runway 27.
Example Sentence 2
During the departure the aircraft followed the SID routing before joining the airway.