The Boeing C-135 Stratolifter is a transport aircraft derived from the prototype Boeing 367-80 jet airliner 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.

The Boeing 367-80 is a retired American four-engined jet prototype aircraft built by Boeing to demonstrate the advantages of jet propulsion for commercial aviation. It served as basis for the design of the KC-135 tanker and the 707 airliner.