At just after 11am on February 9, 1969, the first jumbo jet readied to take to the air for its inaugural test flight.
Pilot Jack Waddell fired up one of the huge aeroplane's four mighty Pratt & Whitney jet engines.
As a veteran of World War II, when Waddell flew fighters for the U.S. Navy, he had been on many nerve-racking missions, but perhaps none were as tense as this. For this was no ordinary debut.
With the introduction of the Boeing 747, an opulent age of air travel promised to become affordable for all and change the world as we know it.
Behind Waddell were some 160 tons of aircraft, with a payload of around 54 tons of bulging mail sacks and beer kegs filled with water.
The plane itself was made out of a mind-boggling six million parts, of which a quarter were rivets holding together the 232ft machine.
The Boeing 747 took to the skies on February 9, 1969, and was made out of six million parts, of which a quarter were rivets holding together the 232ft machine
A picture taken on January 13, 1970, shows the aircraft crew from the first commercial flight of the Boeing 747, otherwise known as the 'Jumbo Jet', on board a flight from New York to London for Pan American
This fascinating black and white picture shows Pan American flight attendants serving passengers in the first class cabin of the Boeing 747 Jumbo Jet champagne
First Officer Betsy Carroll, the first woman to pilot a Boeing 747 Jumbo Jet across the Atlantic, sits inside the cockpit of the Jumbo Jet
Pictured: Jess Wallick (left), chief test pilot Jack Wadell (centre) and co-pilot Brien Wygle (right) from the book: Boeing 747: A History: Delivering the Dream By Martin Bowman
The result of 75,000 technical drawings and around 625 days in a wind tunnel, it had so far cost Boeing hundreds of millions of dollars. But then the company did hope it would usher in nothing less than a revolution in the skies.
The factory alone cost $200 million — worth $1.3 billion today — which, at 205 million cubic feet, was the largest building by volume in the world.
Accompanying Waddell was co- pilot Brien Wygle, and chief engineer, Jess Wallick — all equipped with parachutes.
If anything went catastrophically wrong, they would be able to escape from the cockpit via a fireman's pole into the cargo bay, from where they could open a hatch and jump to safety.
Just before taking off, Waddell's boss, Bill Allen, had told him: 'Jack, I hope you understand that the future of the company rides with you guys this morning.'
That had been no understatement. If the test flight failed, then the company risked going down with the plane.
Three flight attendants, in their traditional uniform, stand on the stairwell of the new Boeing Pan American 747 Jumbo Jet
A U.S. pilot and a navigating officer sitting inside the cockpit of the American commercial jet airliner, the Boeing 747, in 1969
In December 1965, Boeing had signed a contract with Pan Am to make 25 747s before the model was even fully developed and tested. Failing to deliver would not only have been a reputational disaster for the company, but an astronomical waste of investment.
Boeing was in debt to investors to the tune of $2 billion — $14 billion today. If the jumbo jet failed, Boeing would have ceased to exist, and tens of thousands of workers would have lost their jobs.