The Tri-Service aircraft designation system is a unified system introduced in 1962 by the United States Department of Defense for designating all U.S. military aircraft. Previously, the U.S. armed services used separate nomenclature systems.
Under the tri-service designation system, officially introduced on 18 September 1962, almost all aircraft receive a unified designation, whether they are operated by the United States Air Force (USAF), United States Navy (USN), United States Marine Corps (USMC), United States Army, United States Space Force (USSF), or United States Coast Guard (USCG). Experimental aircraft operated by manufacturers or by NASA are also often assigned designations from the X-series of the tri-service system.[1]
The 1962 system was based on the one used by the USAF between 1948 and 1962, which was in turn based on the type, model, series USAAS/USAAC/USAAF system used from 1924 to 1948. The 1962 system has been modified and updated since introduction.