United States military aircraft serial numbers

On the Northrop Grumman B-2 Spirit bomber, lacking a tail, the number appears on the nose gear door.

The aircraft, a Wright Model A, was used by the aviation section of the United States Army Signal Corps and was issued with serial number 1.

On 1 July 1921, a new serial system was introduced that was based on the United States Fiscal Year, which continues to the present day.

In 1926, when the USAAS became the United States Army Air Corps (USAAC), the sequence continued unchanged.

In late June 1941, when the USAAC became the United States Army Air Forces (USAAF), the sequence continued unchanged, and the displayed number, normally shown on the fixed vertical stabilizer's sides, usually omitted the first digit of the year of the contract issuance.

In 1911, the United States Navy (USN) purchased its first aircraft, a Curtiss Triad pusher floatplane.

In 1926, the United States Coast Guard purchased its own aircraft, and they were assigned one or two-digit serial numbers.

In 1945, the V prefix was removed and replaced with digit 1 to make four-digit serial numbers, which continues to the present.

An aircraft in the first 10 units purchased in the fiscal year is often referred to as "Balls-(number)" – for example, NASA's B-52B, the oldest B-52 in service until its retirement, was known as Balls 8.

In 1969, camouflaged tactical aircraft were marked with a modified presentation with the fiscal year followed by the last three digits of the serial number.

Each Navy and Marine Corps aircraft normally has its Bureau Number plus the type designation marked in small letters on the rear fuselage.