The Boeing 707 entered service with Pan Am on 26 October 1958, flying New York to Paris. The Comet had beaten it into service by six years and the Comet 4 by three weeks. The 707 is nonetheless the aircraft that started the jet age, because it was the first jet airliner that made commercial sense at scale.
The gamble
Boeing was a bomber manufacturer with almost no presence in commercial aviation. In 1952 it committed roughly a quarter of the company's net worth to building a prototype jet transport, the Model 367-80 — the "Dash 80" — with no orders and no customer.
The bet was that the US Air Force would want a jet tanker and that airlines would follow. The Air Force did, ordering the KC-135. The airlines took longer to convince.
Test pilot Tex Johnston barrel-rolled the Dash 80 over the Seattle hydroplane races in 1955, in front of airline executives. Boeing's president was reportedly furious. The orders came.
Why it beat the Comet
Size and range. The 707 carried significantly more passengers further, which meant a lower cost per seat on exactly the routes where jets mattered most — transatlantic and transcontinental.
It also benefited directly from the Comet investigation. The fatigue findings were published, and Boeing designed the 707's structure accordingly.
What it changed
New York to London went from a piston-engine journey with a fuel stop to about seven hours nonstop. Within a decade the transatlantic ocean liner had effectively stopped being a way to travel and become a holiday in itself.
The 707 also established the physical template of the jet airliner: swept wing, podded engines slung under it on pylons, cabin above the wing box. Almost every subsequent airliner from every manufacturer follows that arrangement, which is why a 707 and a modern 737 look more alike than they should given seventy years between them.
The downside
Early 707s were extremely loud, and the noise complaints from communities under approach paths began the entire field of aircraft noise regulation. They were also thirsty, which mattered little at 1958 fuel prices and a great deal after 1973.
The long tail
Passenger 707s were largely retired from major airlines by the 1980s, pushed out by noise rules and fuel costs. The military derivatives lasted far longer: the KC-135 tanker fleet, the E-3 Sentry AWACS and various special-mission variants remain in service, some approaching seventy years after the first flight.
Boeing built 1,010 civil 707s. The company that had almost no commercial business in 1952 became the dominant airliner manufacturer in the world, and stayed there for fifty years.