Boeing 707 ushering in the Jet Age. It established Boeing as one of the largest manufacturers of passenger aircraft, and led to the later series of airliners with "7x7" designations. The later 720, 727, 737, and 757 share elements of the 707's fuselage design. The 707 was developed from the Boeing 367-80, a prototype jet first flown in 1954. A larger fuselage cross-section and other modifications resulted in the initial-production 707-120, powered by Pratt & Whitney JT3C turbojet engines, which first flew on December 20, 1957. Pan American World Airways began regular 707 service on October 26, 1958. Later derivatives included the
Boeing 707 engines. Pratt & Whitney, in a joint venture with Seven Q Seven (SQS) and Omega Air, has selected the JT8D-219 as a re-engine powerplant for Boeing 707-based aircraft, calling their modified configuration a 707RE. Northrop Grumman has selected the −219 to re-engine the United States Air Force's fleet of 19 E-8 Joint STARS aircraft, which will allow the J-STARS more time on station due to the engine's greater fuel efficiency. NATO also plans to re-engine their fleet of E-3 Sentry AWACS aircraft. The −219 is publicized as being half the cost of the competing 707 re-engine powerplant, the CFM International