United States military aircraft designation systems

Multiple designation systems have been used to specify United States military aircraft. The first system was introduced in 1911 by the United States Navy, but was discontinued six years later;^[1] the first system similar to that used today was designed in 1919 when the US Army's Aeronautical Division became the United States Army Air Service. Before this, aircraft were put into service under their manufacturers' designations.^[2]