A bloke I was talking to had an interesting theory as to why it was labeled the F-117, despite being a ground attack aircraft rather than a fighter, and the number being out of sequence (everyone was expecting an F-19.
Around the same time as the F-117 aircraft was being developed, Pratt & Whitney PW2000 engine was being developed, which went on to be used in the C-17. The PW2000 was designated by the USAF as the F117 engine. By labelling the F-117 aircraft with the same designation, they were able to hide the development in plain sight. If anyone heard or saw anything about the F-117, they'd assume it was related to the engine, rather than the secret stealth aircraft.
I've never read anything on the internet regarding this theory, but it's an interesting theory nonetheless.
Tanks are called tanks instead of "Caterpillar Machine Gun Destroyers" so the initial design could pretend to be a project related to mobile water tanks which gave an excuse for needing lots of steel plates and engine components.
That story about the F-117/F117 is definitely plausible.
I remember seeing a documentary that had an interview with someone involved in the development who said it was designated F (Fighter) instead of B (Bomber) because it handled more like a fighter than a bomber so they wanted fighter pilots rather than bomber pilots.
No fighter pilot would have applied for the B-117 so F it was.
Don't really believe it but it is a funny thought.
It is an interesting thought, with some precedence. The F-111 Aardvark and the F-105 Thunderchief were labelled as fighter aircraft, but only ever used as bombers.
Theory I've heard was that it was for counterintelligence purposes, but more in the designation of "Fighter" - the thought being that the Soviets wouldn't be as interested in a new black fighter project as they would have been in a similarly black bomber.
Funny, I've heard it's because attack planes are the redheaded stepchild of the air force, and so it's purely a marketing move. DOD and AF brass don't want to fund an attack plane when they can spend money and fancy fighters, and all the pilots want to fly fighter jets.
During the 1990's it was believed [citation needed] that there was a limit on the amount of bomber aircraft the USSR and USA could field. Calling this aircraft a fighter made it not count towards that limit. I actually thought that this was the "well-known" explanation until stumbling upon the uncertainty in this thread.
Around the same time as the F-117 aircraft was being developed, Pratt & Whitney PW2000 engine was being developed, which went on to be used in the C-17. The PW2000 was designated by the USAF as the F117 engine. By labelling the F-117 aircraft with the same designation, they were able to hide the development in plain sight. If anyone heard or saw anything about the F-117, they'd assume it was related to the engine, rather than the secret stealth aircraft.
I've never read anything on the internet regarding this theory, but it's an interesting theory nonetheless.