Leo Marriott - Jets at Sea Naval Aviation in Transition 1945-1955

During the period under review in this book the US Navy applied a system of designations that indicated the operational role of the aircraft and its manufacturer. The first letter(s) indicated the aircrafts function and the second letter the manufacturer. Between the two letters was a number that indicated the sequence of designs or projects from that particular manufacturer. Thus, for example, the well known DC-3 civil airliner became the R4D when used by the US Navy as a military transport, indicating that it was the fourth Transport design (R) produced by Douglas (D). Other numbers and letters could be added to indicate sub variants such as the R4D-5T, indicating a Mark 5 (with different engines) adapted for the Training role (T). In the case of the first design of a particular type the number one was omitted, an example being the Douglas Skyraider, which, as the first Douglas Attack aircraft, was designated AD with a subsequent number for sub variants (e.g. AD-4). One major variation that will often be noted in the text is the prefix X for a prototype and Y for a pre-production aircraft, an example being the XF6U-1 Cutlass - prototype of the sixth fighter design by Chance Vought. Relevant manufacturers and function codes are given below, although this list is not exhaustive and many minor functions and manufacturers are omitted for the sake of brevity. This basic system remained in use until 1962 when a common unified designation system was introduced for all US military aircraft (Army, Navy and Air Force).