List of United States Air Force aircraft designations (1919–1962)

This list of United States Air Force aircraft designations (1919–1962) includes prototype, pre-production and operational type designations under the 1919 and 1924 United States Army Air Service aircraft designation systems, which were used by the United States Air Force and its predecessors until the introduction of the unified United States Tri-Service aircraft designation system in 1962.

Prior to 1919, all aircraft flown by the Army Air Service were referred to by the designation given to them by their manufacturer.

In 1926, the three-category system was scrapped and all bombers subsequently built were placed in the B- sequence.

A short-lived designation used from 1935–1936 to refer to three long-range bomber projects commissioned by the Army Air Corps.

The USAF established a separate sequence for purpose-built research aircraft in 1946.

Designated P- for "pursuit" until June 1948, nine months after the United States Air Force was founded.

In 1941, the category letter R- was allotted for "rotary wing" aircraft, and this designation was used until the founding of the United States Air Force in 1947, at which point the category letter was changed to H-, for "helicopter".