Boeing C-135 Stratolifter
The Boeing C-135 Stratolifter is a transport aircraft derived from the prototype Boeing 367-80 jet airliner (also the basis for the 707) in the early 1950s. It has a narrower fuselage and is shorter than the 707. Boeing gave the aircraft the internal designation of Model 717. Since the first one was built in August 1956, the C-135 and its variants have been a fixture of the United States Air Force.
A large majority of the 820 units were developed as KC-135A Stratotankers for mid-air refueling. However, they have also performed numerous transport and special-duty functions. Forty-five base-model aircraft were built as C-135A or C-135B transports with the tanking equipment excluded. As is the case with the KC-135, the C-135 is also recognized as the Model 717 by Boeing.
Fifteen C-135As, powered by Pratt & Whitney J57 turbojets, were built. In later years, almost all were upgraded with Pratt & Whitney TF33 turbofan engines and wide-span tail planes, and were re-designated C-135E. Most were converted to various special roles, including airborne command posts, missile-tracking platforms, and VIP transports, and were withdrawn throughout the 1990s.