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 Air Force One, the secure transport for the President of the United States. These models were in operational use from 1962 to 1990. The two aircraft remain on display: SAM 26000 is at the National Museum of the United States Air Force near Dayton, Ohio and SAM 27000 is at the Ronald Reagan Presidential Library in Simi Valley, California. The Canadian Forces also operated the Boeing 707 with the designation CC-137 Husky (707-347C) from 1971 to 1997. Boeing 717 was the company designation for C-135 Stratolifter and KC-135 Stratotanker derivatives of the 367-80. The designation was later reused in renaming