Military Aircraft Designations

Purely speculation on my part, but the F-111 would probably have still been given an ‘F’ designation even without the antichrist McNamara’s intervention. Giving aircraft that were strike/tactical bombers the ‘F’ designation under the purely nominal theory that they were ‘fighter-bombers’ when they were never going to be used as actual fighters was fairly common. The Republic F-84 Thunderjet was at least in theory supposed to be a fighter-bomber as designed, but was used almost exclusively as a tactical bomber. The Republic F-105 Thunderchief which replaced it didn’t even seriously bother to play up any ‘fighter’ angle as a ‘fighter-bomber’ in its development:

It was originally designed as a single-seat, nuclear-attack aircraft;

As a follow-on to the Mach 1 capable North American F-100 Super Sabre, the F-105 was also armed with missiles and a rotary cannon; however, its design was tailored to high-speed low-altitude penetration carrying a single nuclear weapon internally.

In the wiki link on designations it lists H-55 Osage with a verbal description as a trainer. When I was at Ft Rucker (now Novosel) 1980-81, it was designated TH-55.

Sorry, forgot to thank EnolaStraight for the link.

The ‘Thud’ was originally intended as fast penetration nuclear delivery vehicle, and eventually became the mainstay of Suppression of Enemy Air Defenses (SEAD) forces, taking out the SAM sites that the Russians deployed in Viet Nam to test NATO capability. In general, as warfare theories become more advanced, the tools become more specialized until a radical change causes a paradigm shift in tactics (the way advanced long distance and inexpensive drones are doing now).

Stranger

The A-12 was ordered by the CIA and as a civilian plane didn’t fall under any military aircraft designation system. A-12 was a Lockheed internal designation, the 12th design in the Archangel project. Some of the earlier designs are shown on the wikipedia page.