The Douglas C-132 was a proposed transport aircraft, based on the company's C-124 Globemaster II. Design studies began in 1951 but the project was cancelled in 1957 by the USAF. No prototype was built and the project did not get past the mock-up stage. The C-132 was to be powered by four 15,000 shp (11,000 kW) Pratt & Whitney XT57 (PT5) turboprops, mounted on a swept wing. An air refueling version, the XKC-132 was also proposed, but it would only have utilized the probe and drogue (P&D) air refueling system and that system, used primarily by the US Navy, did not find favor with the USAF. One XT57 was installed in the nose of a C-124 (AF serial number 52-1069) for testing. Projected speed was to be 418 knots (774 km/h) with a range of 2,200 nautical miles (4,100 km) and a maximum payload of 137,000 pounds.