Inside the Boeing KC-135 "Stratotanker" - Castle Air Museum

The Boeing KC-135 Stratotanker is an American military aerial refueling tanker aircraft that was developed from the Boeing 367-80 prototype, alongside the Boeing 707 airliner. It has a narrower fuselage and is shorter than the 707. Boeing gave the aircraft the internal designation of Model 717 (number later assigned to a different Boeing aircraft). The KC-135 was the United States Air Force (USAF)'s first jet-powered refueling tanker and replaced the KC-97 Stratofreighter. The KC-135 was initially tasked with refueling strategic bombers, but it was used extensively in the Vietnam War and later conflicts such as Operation Desert Storm to extend the range and endurance of US tactical fighters and bombers.The KC-135 entered service with the USAF in 1957; it is one of nine military fixed-wing aircraft with over 60 years of continuous service with its original operator. The KC-135 was supplemented by the larger McDonnell Douglas KC-10 Extender. Studies have concluded that many of the aircraft could be flown until 2030, although maintenance costs have greatly increased. The KC-135 is to be partially replaced by the Boeing KC-46 Pegasus.

Starting in 1950 the USAF operated the world's first production aerial tanker, the Boeing KC-97 Stratofreighter, a gasoline fueled piston-engined Boeing Stratocruiser (USAF designation C-97 Stratofreighter) with a Boeing-developed flying boom and extra kerosene (jet fuel) tanks feeding the boom. The Stratocruiser airliner itself was developed from the Boeing B-29 Superfortress bomber after World War II. In the KC-97, the mixed gasoline/kerosene fuel system was clearly not desirable and it was obvious that a jet-powered tanker aircraft would be the next development, having a single type of fuel for both its own engines and for passing to receiver aircraft. The 230 mph (370 km/h) cruise speed of the slower, piston-engined KC-97 was also a serious issue, as using it as an aerial tanker forced the newer jet-powered military aircraft to slow down to mate with the tanker's boom.Like its sibling, the commercial Boeing 707 jet airliner, the KC-135 was derived from the Boeing 367-80 jet transport "proof of concept" demonstrator, which was commonly called the "Dash-80". The KC-135 is similar in appearance to the 707, but has a narrower fuselage and is shorter than the 707. The KC-135 predates the 707, and is structurally quite different from the civilian airliner. Boeing gave the future KC-135 tanker the initial designation Model 717.

In 1954 USAF's Strategic Air Command (SAC) held a competition for a jet-powered aerial refueling tanker. Lockheed Corporation's tanker version of the proposed Lockheed L-193 airliner with rear fuselage-mounted engines was declared the winner in 1955. Since Boeing's proposal was already flying, the KC-135 could be delivered two years earlier and Air Force Secretary Harold E. Talbott ordered 250 KC-135 tankers until Lockheed's design could be manufactured. In the end, orders for the Lockheed tanker were dropped rather than supporting two tanker designs. Lockheed never produced its jet airliner, while Boeing would eventually dominate the market with a family of airliners based on the 707.In 1954, the USAF placed an initial order for 29 KC-135As, the first of an eventual 820 of all variants of the basic C-135 family. The first aircraft flew in August 1956 and the initial production Stratotanker was delivered to Castle Air Force Base, California, in June 1957. The last KC-135 was delivered to the USAF in 1965.

More About Castle Air Museum:
Castle Air Museum affords visitors from the region and throughout the world the opportunity to learn the costly sacrifices of the men and women who designed, built, maintained and flew these aircraft into hostile skies to defend freedom and liberty with many making the ultimate sacrifice. The Museum also serves to educate on the past milestones in aviation and what the future of aerospace may hold in store.

Castle Air Museum, located in the heart of California’s San Joaquin Valley is the largest aviation museum between Southern California and the State of Washington with over seventy restored vintage military aircraft on static exhibit with more to arrive in the future! The Museum is adjacent to the former Castle Air Force Base, now Castle Airport, and officially opened to the public in 1981 as a non-profit 501c3 organization with a mission “to preserve military aviation heritage for future generations.” Today the Museum has evolved into a premier showcase for families, history buffs, schools, tourists, and aviation enthusiasts.

Visit Castle Air Museum Online:
https://www.castleairmuseum.org