I came across my old handbook from the 'Ground Observers'. The famous P-51 airplane is shown as a F-51. Why

Question

I am a R/C airplane nut. I recently bought a P-51 Mustang model & am assembling it now. I am hearing that this 'plane has a ton of history around it. I am noticing, also, that there were different models were built...P-51-A, P-51-B, P-51-C, and the most popular,
P-51-D. In an Aircraft Documentation book, I have, there is no mention of the F-51 series. In my 'handbook there is also shown a F-82 twin mustang...but my Documention book calls it a P-82.
With my Ground Observers' Guide being a genuine Air Force Manual (50-12) printed: 1 November 1951, I highly doubt a typo on their part.

Answer 1

All P- (Pursuit) aircraft were re-designated F- (Fighter) in the late 1940s.

Answer 2

In 1946, the designation P-51D (P for pursuit) was changed to F-51D (F for fighter) because of a new designation scheme when the Army Air Forces were split off to become the new Air Force. During the Korean War, F-51s, though obsolete as fighters, were used as tactical bombers.

The F-51 was adopted by many air forces. The last Mustangs were discarded by the USAF in 1957 but remained in National Guard service until 1964. Many remain airworthy across the globe, in private hands. A few of those have been modified for extra speed for competing in air racing.

Answer 3

IB has it correct