The United States military aircraft engine designation system was introduced in 1926, originally for piston engines it was expanded in the 1947 to include a separate system for jet and rocket engines.
The United States military aircraft engine designation system was introduced in 1926, originally for piston engines it was expanded in the 1947 to include a separate system for jet and rocket engines. (en)
The United States military aircraft engine designation system was introduced in 1926, originally for piston engines it was expanded in the 1947 to include a separate system for jet and rocket engines. (en)