Definition
In ATC usage, refers to the act of submitting a flight plan to the appropriate aviation authority (typically Flight Service or via an electronic filing system) prior to flight, providing details such as route, altitude, departure and destination, aircraft information, and estimated times.
Plain English
A flight plan is 'filed' once the pilot has formally sent it in and the system has accepted it on record. It is now on file with the authorities, ready to be activated when the flight begins.
Context Anchor
Seen in flight-plan discussions, preflight planning, dispatch paperwork, and radio or system messages about whether a flight plan has been submitted.
Derivation
From the Old French 'filer,' meaning to arrange documents on a string or wire for orderly storage. To 'file' something is to place it formally on record. In aviation, a flight plan is 'filed' when it is officially placed on record with ATC.
Why Pilots Care
A filed flight plan activates safety services including search and rescue if the aircraft does not arrive.
Intuition Check
Filed does not mean “approved” or “ready to go.” It means the flight-plan information has been submitted and is on record.
Example Sentence 1
The pilot filed an IFR flight plan an hour before departure so ATC would have the route on record when she called for her clearance.
Example Sentence 2
Once the flight plan is filed, ATC can provide routing and the departure time is logged for safety monitoring.