New Jet Flies High. The gleaming Boeing 707, America's first jet transport, soars above the snow-capped peak of Mount Rainier, near Seattle, Washington. The sleek, four-jet prototype, which made it maiden flight on July 15th, has already been flown at altitudes above 42,000 feet and at speeds of more than 550 miles per hour. Washington, USA. 28 July 1954.