Boeing 707 ContinentalBoeing 707 Continental Airlines airplane model. In August 1952, the company took the bold step of gambling some 16 million dollars to build the prototype of a completely new turbojet powered civil transport. Boeing was sufficiently realistic to appreciate from the very beginning that its large private venture investment, even in 1952 dollars, was nowhere near the amount that would be needed if large scale production of a civil airliner was to become a