How to Tell the Year on a KC-135 Aircraft

A KC-135 refuels two fighter jets at the same time.

The KC-135 Stratotanker is an Air Force aerial-refueling plane that first saw service in 1957. Boeing continued to make this four-engine jet until 1965. The KC-135 is a military version of the Boeing 707 airliner, but it has been modified to carry jet fuel and deliver it to other planes and helicopters in flight. During refueling, the Stratotanker uses a boom that extends from the rear of the plane. It can also use a "drogue," a small parachute-like device that attaches to the fuel probes on some aircraft.

Instructions

1. Find the tail number or serial number on a particular KC-135 Stratotanker. Tail numbers are usually on the tall fin at the back of the plane. The number will have either five or six digits, depending on the year the plane was built.

2. Look at a five-digit tail number and note what the first digit is. This is the last digit of the year the plane was ordered. For example, the number 35444 would mean the plane was ordered in 1963. In the 1950s and 1960s, when turn-around times were shorter, a military plane was often built the same year it was ordered.

3. Check to see if the KC-135 has a six-digit number, such as 635444. The first two digits of this serial number indicate the plane is also from 1963.

References

• Grissom Air Reserve Base; KC-135R Stratotanker; January 2011
• Joseph F. Baugher: USAF Aircraft Serial Numbers -- 1908 to Present