Definition
A request originated by a flight service station or air traffic control facility for information concerning an overdue IFR or VFR aircraft.
Plain English
A formal request sent out by ATC or flight service when an aircraft is overdue, asking other facilities or stations whether they have any information about where the aircraft is.
Context Anchor
Seen in search-and-rescue and flight plan procedures, especially when a pilot is overdue or has not closed a VFR flight plan.
Derivation
INREQ is a contraction of 'Information Request.' The acronym is used in ATC teletype and message traffic where short codes save time when relaying urgent information between facilities.
Why Pilots Care
Enables quick access to needed flight information without requiring a full flight plan amendment or direct voice contact.
Intuition Check
Do not read “request” here as a pilot asking ATC for something. In this context, it is Flight Service asking other sources for information about an overdue aircraft.
Example Sentence 1
When the IFR flight failed to report at its expected time, the controller issued an INREQ to nearby facilities to check whether anyone had communicated with the aircraft.
Example Sentence 2
After the INREQ was received, the controller replied with the current flight plan information.