Boeing Designed the 747 in 28 Months and Built the World's Biggest Building to Hold It

In April 1966, Juan Trippe of Pan American World Airways placed an order for 25 jumbo jets at $525 million — at the time the largest airliner order in history — for an airplane that didn't yet exist. Trippe wanted something two and a half times the size of a Boeing 707 with operating costs per passenger 30 percent lower. Boeing assigned Joe Sutter to lead the design, working on a 28-month delivery schedule that everyone involved considered impossible. The team became known as the Incredibles. At its peak it employed about 50,000 engineers, mechanics, and tradespeople in two shifts.

The airplane was so much larger than anything Boeing had built that no existing factory could assemble it. Boeing bought a 780-acre site near Everett, Washington, in 1966 and constructed a new plant on it. By the time the 747 prototype rolled out on September 30, 1968, the Everett plant was the largest building in the world by enclosed volume — about 472 million cubic feet — a status it held for several decades. The first flight followed on February 9, 1969. Pan Am's first commercial route, from New York to London, opened on January 22, 1970.

The 747 stayed in production for 54 years. The last airframe — a freighter for Atlas Air — left the Everett line on January 31, 2023, after 1,574 had been built across passenger, freight, and military variants. The aircraft held the title of world's largest passenger airliner from 1970 until the Airbus A380 entered service in 2007, a 37-year run unmatched in commercial aviation. The hump containing the second-deck lounge — by now mostly converted to cargo or extra business-class — exists because Boeing's customers thought the 747 might lose passenger duty to supersonic transports and wanted it convertible to freight.