C-135

C-135 Stratolifter
C-135C Speckled Trout
Role	Transport aircraft
National origin	United States
Manufacturer	Boeing
First flight	17 August 1956
Introduction	June 1957
Status	Active service
Primary user	United States Air Force
Produced	1954–1965
Number built	803
Unit cost	US$39.6 million (FY98 constant dollars)
Developed from	Boeing 367-80
Variants	Boeing KC-135 Stratotanker Boeing EC-135 Boeing NC-135 Boeing RC-135 OC-135B Open Skies WC-135 Constant Phoenix

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to various special roles, including airborne command posts, missile-tracking platforms, and VIP transports, and were withdrawn throughout the 1990s.

Thirty C-135Bs were built with the TF33 turbofans and wide-span tail planes from the start, and a small number remain in service in their original form. Ten were modified for a weather reconnaissance (flying through radioactive clouds from nuclear tests or other agents) role and designated WC-135B Stratolifter (Constant Phoenix in later versions). Additional airframes were converted to RC-135s from the 1970s to 2006, and remain in service with further equipment upgrades installed.

The C-135C designation applies to three WC-135B weather reconnaissance aircraft, which reverted to transport status. Most of the other C-135Bs were converted to various special mission variants following their service with the Military Airlift Command.

Although most of the remaining C-135 aircraft are used for transporting senior military leaders and other high-ranking dignitaries, the C-135C communications aircraft serves as an aerial test-bed for emerging technologies. Developmental tests using this aircraft have demonstrated the capability to fly precision approaches using a local area differential GPS system. This modified C-135 has been fitted with a millimeter wave camera and a radome to test the camera’s generation of video images of the forward scene in low-visibility conditions. The aircraft, which in the VIP/Distinguished Visitor (DV) transport role seats 14 passengers, also gives a Joint Forces Air Component Commander (JFACC) a limited ability to plan and control the simulated battle while in the air en route to the crisis area.