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 (e.g., B-17, P-51, F-86) to identify the aircraft's primary purpose.
This naming system was simplified in 1924 from cumbersome multi-letter designations, leading to single letters like "P" for pursuit.
During World War II, common designations included "B" for bomber, "P" for patrol, and "PT" or "AT" for trainers.
In 1948, the newly formed U.S. Air Force changed the "P" designation to "F" for fighter, better reflecting the specialized combat role of 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.