U. S. Army Aircraft Designations 1939-1945
If you have struggled through my earlier explanation of the U.S. Navys aircraft designation system, I have some good news for you - the Armys is simpler! In most cases, a one or two letter type code followed by a number is all you need to know to designate most Army Air Corps and Army Air Force aircraft in World War II. The bad news is that they had a habit of tacking on some extra information to the front and back of the designation, to completely define each planes purpose and manufacturer.
Combat aircraft typically started with A (Attack), B (Bomber) or P (Pursuit, i.e. fighter). Large cargo and troop carrying planes started with C (Cargo/Transport), while smaller ones started with UC (Utility Transport). Observation planes started with O, although many of these later became redesignated L (Liaison). Finally, the thousands of training aircraft were called PT (Primary Trainers), BT (Basic Trainers) and AT (Advanced Trainers). If you can remember these basics, you will be off to a good start.
Following the aircraft type code came a number, indicating how many of that type had been designed or ordered by the USAAC. Thus, the B-17 was the 17th bomber, the P-40 was the 40th fighter (pursuit) and C-47 the 47th transport designated or actually ordered. Some numbers were assigned to designs which were never built, and the sequence of numbers does not always indicate which came first.
So, in general, we talk of L-5s, BT-13s, AT-6s, C-46s, B-24s, etc. when we want to designate a specific design or family of aircraft produced by one manufacturer. When we start to designate sub-types within a design, that is when it gets a bit more detailed, as we will explain in the following. Finally, many U.S. Army aircraft had a popular name, such as Mustang for the P-51, Flying Fortress for the B-17 and Texan for the AT-6. These names were often dreamed up by the manufacturers, but as the war went on, most designs acquired a popular name. Some of these are listed in a separate article.
Now into the meat of the system, for those who enjoy tables and other clerical punishments.
The Basic Components of the Army's Designation System
Here are four examples of USAAC aircraft, to see how each letter or number is used to form the planes designation. The first two include information about when and where the aircraft was built.
The last two or three components were not commonly used when discussing the aircraft type, but all were included on the planes data plate, to fully identify the aircraft. Sometimes the block number is not included but the manufacturer code is, i.e. B-29A-BN or C-47B-DK.
The following tables list the letter codes used for each component type.
Aircraft Types or Classes
The following types were the most common assigned to aircraft immediately before or during World War II.
The More Common Classes or Types
Those marked with an asterisk(*) were not as common.
The following types were applied to gliders (non-powered aircraft) only and not all types saw actual production or use.
Special Target & Guided Bomb Classes
These are special types given to targets and early guided bombs and control aircraft.
The following types may be encountered in tables and discussions of World War II aircraft, although by 1941, most were obsolete and not used anymore.
The model number was sequential with each type, i.e. from B-1, P-1, C-1, etc. as each new designation was given, even if the aircraft was never produced. Early in the war, a change of the type or make of engine in a design would cause a new number designation, as when a B-17 was fitted with Allison engines to become the XB-38. Later on, such changes were typically indicated by a new series letter (see below).
Usually, the first pre-production batch of a design did not have a series suffix letter, i.e. B-26, P-38, and the first full production version bore the series letter A, although there are a number of exceptions. Subsequent modifications to the design, including different "dash" models of engines, would usually result in the next series letter, i.e. B, C, D, etc. being added to the designation.
Thus a P-51D was the fourth in the P-51 series to be designed or produced. The letters I and O were not used, and some series were never produced and thus skipped.
Special Status or Purpose Codes
These codes could be added onto the front of a normal designation, to indicate modifications or use for a new or special purpose. Examples include CB-24, a B-24 modified to carry cargo (but not a C-87), TB-25, a B-25 used for training or WB-29, a B-29 used as a weather recon aircraft.
Block Numbers and Manufacturers Codes
Although not used in casual discussions, these two elements of an aircrafts designation actually defined when and where an aircraft was built and by whom. The block numbers started with 1 and were usually assigned in multiples of five, i.e. 5, 10, 15, etc. to allow modifications to be indicated by intervening numbers. As changes were made in the design on the production line, a new block number would be assigned.
The manufacturers code told not only what company built the aircraft, but in which plant it was assembled. Again, this was to help deal with minor differences and changes within the system, especially when trying to join spare parts to the correct airplane.
The following is a rather lengthy list of codes as of the end of the war.
A list of U.S. aircraft popular names, both Army and Navy, and their British equivalents is included as a separate article.
Non-Standard Aircraft Designations
Just when you though this was somewhat straight forward, we find out our (the Confederate Air Force's) B-24 is really a LB-30, and an AT-19 painted in British Royal Navy markings is called a V-77! In a few cases, a design or variant was produced for a foreign country but not used by the U.S. These odd balls were often designed by their manufacturers company project number, sometimes mixed with official type codes.
The best known examples were our LB-30, an early version of the B-24 Liberator built for the British, the 30th design in Consolidateds "Land Bomber" series, and the P-400 and P-322, export versions of the P-39 and P-38 fighters respectively, which were taken over and used by the USAAC, carrying company project numbers added to the P for pursuit. The V-77 was Stinsons (a division of Consolidated Vultee) project code for the British version of the AT-19/UC-81.
There are a few other examples, but they are not too common.
Sources and Further Reading
The standard reference for USAAC aircraft designations is James C. Faheys U.S. Army Aircraft (Heavier-Than-Air) 1908-1946, first published in 1946. An excellent single source on the aircraft and their designations is United States Military Aircraft Since 1909 by Gordon Swanborough and Peter M. Bowers, published by Putnam and others.
Kenneth Munsons American Aircraft of World War 2 in colour is another book with useful tables and appendices on aircraft names and designations.
All material not specifically credited is Copyright © by Randy Wilson.
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