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 377 Stratocruiser 377s (and United DC-6s) were scheduled between Honolulu and San Francisco () in 9 h 45 min each way. The longest (by distance) 377 nonstop flights were made by Pan Am from Tokyo to Honolulu during four winter seasons beginning in 1952–1953. In January 1953, two nonstops a week were scheduled with a flight time of 11 hr 1 min due to strong tailwinds; the following August all flights took 19 hours, with a stop at the Wake Island Airfield. By 1960, Stratocruisers were being superseded by jets, such as the de Havilland Comet, Boeing 707, and Douglas DC-8. The