United States military aircraft designation systems

The first system was introduced in 1911 by the United States Navy, but was discontinued six years later;[1] the first system similar to that used today was designed in 1919 when the US Army's Aeronautical Division became the United States Army Air Service.

[2] During this period, type designations used by the United States Army Air Service consisted of a two or three letter abbreviation of the aircraft's purpose.

[2] In 1947 when the Air Force became a separate service, the designation system was extensively overhauled, with several categories being discontinued and others renamed.

[7] In contrast with its other aircraft, the Navy's four rigid airships were treated as commissioned warships, and were given hull classification symbols.

DoD Directive 4120.15, first issued in 1971 and most recently updated in 2020 (4120.15E incorporating Change 02 "Designating and Naming Military Aerospace Vehicles") is implemented via Air Force Instruction 16-401/Army Regulation 70-50/Naval Air Systems Command Instruction (NAVAIRINST) 13100.16 (3 November 2020) and describes both systems.