In April 1966, Pan Am became the first of twenty-six airlines to pre-order 747s, which Boeing undertook to start delivering be the end of the decade. Pan Am again partnered Boeing along with Pratt and Whitney in the design of a new turbofan engine that would produce enough power for the enormous airliner. In spite of the limited development time, the first prototype 747 rolled out of Boeing’s purpose-built assembly plant at Paine Field near Everett, Washington, on 30th September 1968.
On 9th February 1969, the first air-worthy prototype called City of Everett made its maiden flight. The flight crew comprised test pilots Jack Waddell and Brien Wygle, and flight engineer Jess Wallick. Apart from a minor fault with one of the flaps the crew reported that the aircraft handled extremely well in flight.
Flight tests continued for the next few months during which time the engineers ironed out any problems, particularly with the engines. On 15th January 1970 Pan Am took possession of the first production 747s that entered service between New York and London a week later. Over the next forty years development continued on the 747 with Boeing manufacturing a number of variants for carrying cargo as well as passengers, including the President of the United States, and even giving a piggy-back to the prototype Space Shuttle.