Before the Department of Defense decided to revamp the whole system to apply across all branches in 1962, each branch of the United States Armed Forces (Army, Navy, Marines, Air Force and Coast Guard) had their own system of designating an aircraft (well, the Navy, Marines and Coast Guard shared the same one), and it could get a tad confusing.

What was so confusing, you might ask?  Well, look at the Air Force C-47 Skytrain… unless you wanted the Navy’s, which was designated as an R4D.


 

How about the Army’s L-19 Bird Dog?  The Navy had that designated as an OE-1.

How about a B-17 Flying Fortress, that’s hard to confuse, right?  Well, the Navy and Coast Guard had ‘em too – as a patrol craft designated PB-1.

It was even confusing within a branch.  For example, the Navy’s Chance Vought F4U Corsair… unless it was made without the folding wings for the Marines by Goodyear, in which case it was an FG Corsair.  But if it was made by Brewster, it was an F3A Corsair.  And if it was the attack variant, it was an AU Corsair.

Oh, and the mess with the Grumman F9F… if it was an -6 -7 or -8 model, it had swept back wings and was a “Cougar”, but if it was an  -2, -4 or -5, it had straight out wings, and was a “Tiger”.

As well, the Navy’s old designation could have errors due to a manufacturer's code letter being reassigned to a new company after the original one had gone out of business. Since the numbering sequences for the new manufacturer were always restarted from 1, this could lead to the re-use of a designation when an aircraft was designed for the same role as one of the earlier manufacturer.

  The previously mentioned FG designation, for example – its first usage was for an Eberhart Comanche single seat fighter in the 1920s, but later used for the Goodyear license for Corsairs in the 1940s. 

And, looking at the Navy (the Marine Corps and Coast Guard as well), this wasn’t the first redesignation – there’s actually been several.  Naval Aviation’s designation system began in 1911, and in that designation system, aircraft were designated by a letter assigned to the current manufacturers – with more letters were added to define not only manufacturer but also type of aircraft.

In 1914, the Navy created a new system that identified aircraft with one letter indicating aircraft class and a second letter defining aircraft type. Existing aircraft were redesignated alphabetically into the new system.

From 1917-1922, however, there was no standard system of designation - manufacturer's designations were used during this time, resulting in a variety of different designations.

In 1922, the Bureau of Aeronautics was reorganized, with a new system was brought into use.  Then in 1923, it was decided that the emphasis should be placed on type of aircraft, not the manufacturer, so the manufacturer's letter was placed after the mission letter. This new system was divided into two classes, airplanes and airships, and remained in effect until 1962.

Not that there weren’t redesignations elsewhere.  From 1909-1919, there was no organized system of designation for Army aircraft; all aircraft were operated by the designations of individual manufacturers.  

After establishing the Army Air Service in 1919, a designation system was adopted that utilized 15 basic mission symbols, along with other miscellaneous symbols, followed by a design number.  Over the years, new mission symbols were added, modified mission and status symbols were introduced, and eventually, the original 15 became obsolete. And during WWII, many new mission symbols were added, redesignated, overlapped, and discontinued, resulting in many ambiguities and confusions.  During this time it became the Army Air Corps… and then the Army Air Forces… and then…

1948 – the Army Air Forces is completely separated from the Army to become the Air Force, with a new system of designation for its aircraft.

In 1956, the Army adopted a simple designation system for its aircraft, consisting of six symbols plus a design number.

And then in 1962, all branches are put under a single Designation System that is discussed in another article.