GROUND OBSERVER CORPS AIRCRAFT REPORT: United States. 1951. To ensure rapid transmission of information on aircraft detected by Observer Posts, the Ground Observer Corps adopted a standard Aircraft Flash Message. Components of the message included:
1 - NUMBER OF AIRCRAFT: Reported as ONE, TWO, THREE, FOUR, MANY (if the number of aircraft could not be determined - otherwise the number in the formation would be reported), or UNKNOWN.
2 - TYPE OF AIRCRAFT: Reported as SINGLE (single engine propeller driven aircraft), BI (twin engine propeller driven aircraft), MULTI (three or more engine propeller driven aircraft), or JET (any jet propelled aircraft). Aircraft with mixed engine types, such as the combination jet and propeller driven B-36 bomber, were reported as though propeller driven.
3 - FUNCTION OF AIRCRAFT: Reported as FIGHTER, BOMBER, CARGO (including all airliners), SEAPLANE, TRAINER, or UNKNOWN.
4 - ALTITUDE OF AIRCRAFT: Reported as VERY LOW (under 1,000 feet), LOW (1,000 to 5,000 feet), HIGH (5,000 feet to 15,000 feet), and VERY HIGH (aircraft that can barely be seen or cannot be seen and are reported based on either hearing weak engine noises or seeing vapor trails).
5 - TIME DELAY IN REPORTING: The time difference between the time the aircraft was nearest the Observer post and the time the Filter Center answered "Air Defense, Go Ahead" in minutes rounded to the nearest minute. Delays of under 30 seconds were reported as NO DELAY. Tracks older than 6 minutes were only reported in areas where Observer coverage was sparse.
6 - CODE NAME OF OBSERVER POST: Reported as the GEOREF location of the Observer post.
7 - DIRECTION OF AIRCRAFT FROM OBSERVER POST: Reported at the point the aircraft is closest to the post by the eight points of the compass, NORTH, NORTHEAST, EAST, SOUTHEAST, SOUTH, SOUTHWEST, WEST, NORTHWEST, or as OVERHEAD if the aircraft passed within one half mile of the post.
8 - DISTANCE AIRCRAFT FROM OBSERVER POST: Reported at the point the aircraft is closest to the post as the distance in miles. Aircraft passing within one half mile of the post were reported as OVERHEAD.
9 - DIRECTION OF FLIGHT: Reported by the eight points of the compass, NORTH, NORTHEAST, EAST, SOUTHEAST, SOUTH, SOUTHWEST, WEST, or NORTHWEST, preceded by the word FLYING.
10 - SPECIAL REMARKS: Used to report additional information not covered in the first nine items, including emergencies or aircraft conducting hostile activity.
Sources: United States, Department of the Air Force, Aircraft Recognition for the Ground Observer, AF Manual 355-10, St. Louis, Missouri, United States of America, Von Hoffmann Press, 1955. United States, Department of the Air Force, Ground Observers' Guide, AF Manual 50-12, St. Louis, Missouri, United States of America, Universal Printing Company, 1951.