February 9, 1969, was the first flight of the prototype Boeing 747 ‘Jumbo Jet’. The same basic wing and airframe (although with many modifications over the years), has been flying (and making a profit for its operators) for 40 years. It is an amazing piece of engineering.
Apart from being an amazing aeroplane, it had its hand in saving the economy of Seattle. During 1970, both Seattle and the Boeing company were experiencing a terrible slump, which led some dry-humored locals to erect this sign on the outskirts of the city:
In April 1971, when 747 production was beginning, Boeing had shrunk from 100,000 employees to 38,690. Orders for the 747 starting accumulating, and by October that year, the number of employees had grown to 53,300. A large number of these new jobs in construction and aerospace were linked to the 747 project. More amazingly, Boeing, which was prioritizing its supersonic transport (SST) project thought of the 747 as a stopgap, short run project created to keep one key customer (Juan Trippe, CEO of Pan Am) happy. So they gave the chief engineer job to Joe Sutter, who was barely in his mid 40s when he was handed the job (a chief engineer so young was unheard of at Boeing then). Turns out Joe saved the company, and then the city.
Jon Ostrower has more (with a documentary): First part of the story, and the second part of the story. The original prototype 747 (RA-001) is on display at the airpark of the Museum of Flight at Boeing Field in Seattle: