Boeing Knows How
- The ability to refuel aircraft in flight was an early requirement of the U.S. Air Force. To meet this need, Boeing converted B-29 bombers into tankers at its Wichita, Kan., production facilities.
- Ninety-two KB-29s were equipped with a hose and drogue system developed by Britain's Flight Refueling Limited. Identifying limitations with that system, Boeing began development of the "flying boom," which it incorporated on 116 KB-29s. These boom-equipped tankers were able to more quickly transfer fuel to Strategic Air Command bombers.
- The first purpose-built tanker was the KC-97 Stratotanker. Based on the Model 377 trans-oceanic airliner, the Air Force purchased 811 KC-97 tankers starting in 1950. The transition to jet-powered bombers highlighted the need for a tanker aircraft that could fly higher and faster. From this need came the modern jet tanker.
- In the early 1950s, Boeing began developing a prototype jet aircraft known as the Model 367-80. This aircraft was to serve as the basis for the commercial 707 jetliner and the KC-135 air refueling tanker.
- In 1953, the Air Force had a stated requirement for 200 jet tankers. The three major aircraft manufacturers -- Boeing, Douglas and Lockheed -- all submitted designs. Due to the urgent need, the Air Force purchased 29 KC-135 Stratotankers from Boeing.
- The first KC-135 tanker, known as the “City of Renton,” rolled off the line at Boeing's Renton, Wash., plant on July 18, 1956. From April 1957 to January 1965, The Boeing Company delivered 732 KC-135A tankers to the Air Force.
- The KC-135 underwent a number of upgrades over the years. In 1980, the Air Force awarded a contract to Boeing for integration of the modern CFM-56 high-bypass turbofan engines which had been chosen to replace the 1950-era J-57 jet engines on the KC-135. These more powerful new engines were more fuel-efficient and allowed for greater fuel offload.
- Today, the KC-135 is the workhorse of the U.S. Air Force. In addition to the USAF, France, Singapore and Turkey also fly the KC-135. Seven additional countries fly tankers based on a variant of the 707.
