Decoding the Alphabet: Why U.S. Military Aircraft Names Use Letters

Designations like B-17, P-51, and F-86 evolved from complex acronyms to simple purpose identifiers.

Meg Godlewski

Wednesday, April 15, 2026 at 09:00 AM ET

Verified

Edited By:

Travis Tingle

B-17 bomber [Credit: FLYING Archive]

Key Takeaways:

The U.S. military uses letters in aircraft names to designate their primary purpose, an evolution from more complex multi-letter systems prior to 1924.
During World War II, common designations included "B" for bomber and "P" for pursuit or patrol aircraft.
In 1948, the newly formed U.S. Air Force changed the "P" designation to "F" for fighter, reflecting a more specialized combat role for these aircraft.

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Question: Why did the U.S. military start using letters to name the airplanes it uses? For example B-17, P-51, F-86?

Answer: The letters are the military way of identifying the purpose of the aircraft. Prior to 1924 military aviation had multiple designations for classification of fighter aircraft. For example, “PW” stood for pursuit, water-cooled. So many letters became cumbersome and by 1924 the “P” for pursuit stood alone.