The Boeing 747 is a large wide-body airliner and cargo aircraft manufactured by Boeing Commercial Airplanes in the United States. After introducing the 707 in October 1958, Pan Am wanted a jet 2½ times its size, to reduce its seat cost by 30% to democratize air travel. In 1965, Joe Sutter left the 737 development to design the 747, the first twin aisle airliner. In April 1966, Pan Am ordered 25 747-100 aircraft and in late 1966, Pratt & Whitney agreed to develop its JT9D, a high-bypass turbofan. On September 30, 1968, the first 747 was rolled out of the custom-built Everett Plant, the largest building in the world by volume. The first flight took place on February 9, 1969 and the 747 was certified in December of that year. It entered service with Pan Am on January 22, 1970; it was the first plane dubbed a “Jumbo Jet”.