United States Military Aircraft Designations

Since 1962, all United States services have used a common system of designations based on the USAF system. The central component is the type letter, for example C (Transport). The next element is a numerical type sequence number: thus the 130th transport design (since 1925) is the C-130. Each major development incorporated as a new model of a basic type is given a sequential letter suffix, the second model of the C-130 becoming the C-130B.

Variations in the role within a particular model are given a letter prefix. Hence a version of the C-130B converted for search and rescue became the HC-130B. A second series of prefix letters may be used to designate status; the prototype C-130 was designated YC-130A. Finally there are block numbers and manufacturers' codes, the former indicating minor variations and the latter the factory of manufacture. Block numbers are sequential, but they normally progress by fives or tens. Thus one version of the C-130 was the C-130B-70-LM indicating the seventh block of the C-130B with minor variations and built by Lockheed Marietta. In practice, these last two elements are rarely used.

The type sequence numbers started from 1 again in 1962. In addition, some type letters changed. Many type letters had also changed in 1948, when, for example, the P-51D became the F-51D. Occasionally, type letters are misleading in respect of role (U-2 indicating Utility when the aircraft was a reconnaissance type) or outside the approved range. The SR-71 is a case in point. The type was originally designated A-11, which was the manufacturer's type number. In service it was properly designated F-12, but the reconnaissance version was given the improper designation SR-71.

A full list of the pre-1948, 1948-1962 and post-1962 type prefix letters is set out below.

Role Pre-1948 1948-62 Post1962
Airship     Z
Amphibian OA A  
Anti-submarine     S
Attack A   A
Advanced Trainer AT T T
Aerial Target OQ Q  
Aerial Target Manned PQ Q  
Bomber B B B
Basic Trainer BT T T
Electronic Surveillance   E R
Fighter P F F
Fuel Carrying Glider FG G  
Glide Bomb GB    
Glide Torpedo GT    
Glider CG, FG G  
Helicopter R H H
Jet-propelled Bomb JB    
Liaison L L U
Observation O L, R, U O
Observation Amphibian OA A  
Patrol OA A, R P
Photographic F R R
Powered Glider PG G  
Primary Trainer PT T T
Pursuit (Fighter) P F F
Reconnaissance F R R
Research S X X
Rotary Wing R H H
Supersonic Research S X X
Tactical Support A F, B A
Target, Flying Model OQ Q  
Trainer AT, BT, PT T T
Trainer Glider TG G  
Transport C C C
Transport Glider CG G  
Utility C, L U U

Supplementary Prefix letters have changed less over time and a schedule is set out below.

Role variant Pre-1962 Post-1962
Anti-submarine   S
Calibration A  
Cold-Weather Operations   L
Drone Director D D
Electronics E E
Experimental X X
Grounded Permamently   G
Liaison L  
Medical Evacuation M  
Missile Carrier   M
Obsolete Z  
Observation   O
Parasite Carrier G  
Passenger Transport P V
Photographic F, R R
Project   Z
Prototype, Service Test Y Y
Radio Controlled Drone Q Q
Reconnaissance R R
Search and Rescue   H
Special Tests, Permament N N
Special Tests, Temporary J J
Staff Transport P V
Tactical Support   A
Tanker K K
Trainer T T
Transport C C
Utility U U
Weather Reconnaissance W W


Prior to 1962 Navy and Marine Corps designations focused on the manufacturer, for whom a letter code was used. Thus Lockheed designs used the letter V. Designs from a manufacturer were then allotted a sequential number prefix which was in turn prefixed by a role related letter. The Neptune maritime patrol aircraft was designated P (patrol) 2 (second design from) V (Lockheed), or P2V.

Each major variant was then assigned a hyphenated suffix number, for example P2V-6 being the sixth Neptune model. Finally, role related suffix letters were used to denote variants within the model: the missile carrier version of the P2V-6 was the P2V-6M (when the uniform system was introduced, this designation changed to MP-2F). The manufacturers' codes are set out below.

Manufacturer's code letters
Bell L Interstate R
Boeing-Vertol B Kaman K
Cessna E Lockheed O, V
Consolidated (Convair) Y Martin M
de Havilland Canada C McDonnell H
Douglas D North American J
Fairchild Q Piasecki P
Globe G Piper O
Goodyear G Radioplane D, R
Grumman F Sikorsky S
Gyrodyne N Temco T
Hiller E Vought (LTV) V
Role prefix letters included the following list, the more usual of which have also been used as suffix letters
A Attack KD Target Drone
DS Anti-Submarine Drone M Missile
F Fighter O Observation
G Tanker P Patrol
HC Helicopter, Crane R Transport
HJ, HU Helicopter, Utility RO Rotocycle
HN, HT Helicopter, Training S Anti-Submarine
HO Helicopter, Observation T Trainer
HR Helicopter, Transport U Unmanned Drone, Utility
HS Helicopter, Anti-Submarine   (from 1955)
J Utility (to 1955) W Electronic Search
JR Utility Transport ZP Airship, Patrol
K Radio Controlled ZS Airship, Anti-Submarine