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 adopted a letter-based system for aircraft names to identify their purpose, simplifying from earlier complex designations (e.g., "PW" for pursuit, water-cooled) to single letters like "P" by 1924.
During World War II, specific letters such as "B" for bomber and "P" for patrol were used to classify aircraft types.
In 1948, the U.S. Air Force changed the "P" designation to "F" for "fighter," reflecting a move towards more specialized aircraft roles.

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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.