The destination station transmits an INREQ message to all stations along the route of
flight. The INREQ message should include all information that might assist in search
activities. Enroute stations receiving an INREQ shall check facility records and all flight
plan area airports along the proposed route of flight. Stations shall reply to the INREQ
within 1 hour. When a station is unable to complete the search within 1 hour, the station
must forward a status report to the destination station followed by a final report when
the search is complete.
The INREQ originator shall transmit a cancellation message containing the location of
the aircraft when the aircraft is located.
The destination station transmits an ALNOT message to the Regional Operations
Center, RCC, and those facilities within the search area. The search area is normally
the area extending 50 miles on either side of the proposed route of flight from the last
reported position to the destination. The search area may be expanded to the maximum
range of the aircraft at the request of the RCC or the destination station. Upon receipt of
the ALNOT, immediately conduct a communications search of the flight plan area
airports that were not checked during the INREQ. Request the appropriate law
enforcement agency to check airports that cannot be contacted otherwise. Reply to the
ALNOT within 1 hour.
The ALNOT remains current until the aircraft is located or the search is suspended by
the RCC. The ALNOT originator shall then transmit a cancellation message with the
location of the aircraft, if appropriate.
IFR SAR Procedures
ARTCCs assure that SAR procedures are initiated for overdue IFR aircraft. ARTCCs
serve as the central point for collecting information, coordinating with the RCC, and
conducting communications searches for overdue or missing IFR flights.
ARTCCs also ensure that SAR procedures are initiated for
overdue or missing special visual flight rules (SVFR) aircraft.
For SAR purposes, ARTCCs consider combination VFR/IFR flights and air-filed IFR
flights the same as IFR flights.