Stratospheric airliner (C-75) was requisitioned in World War II, which was mainly used for South American routes and transatlantic routes. 195 1 year, TWA replaced four original 900 horsepower (67 1kw) white GR 1820 star piston engines with white 1200 horsepower engines. Replace the wing with the wing of B 17G. Then it was sold to the French airline Blue Eagle for the Indian-China flight. It was captured in the Vietnam War and used by some airlines, such as Lao Airlines, until the 1970s. The surviving plane is kept at the Smithsonian Institution of the National Air and Space Museum. After being repaired by Boeing retired volunteers for 6 years, he left the hangar on June 23, 20001year. Unfortunately, the plane almost crashed. During the test flight, due to the exhaustion of fuel, it was forced to land on the Elliot coast in the west of downtown Seattle. Fortunately, the damage to the plane was not very serious, and it was repaired again. Now the plane is performing an air show at the Steven Udvar-Harz Center at Washington International Airport.
On August 5, 2003, the world's last Boeing S-307 high-altitude passenger plane completed its last voyage and landed smoothly at Dulles International Airport in Virginia, USA. Later, it will be transported to the Smithsonian Air and Space Museum and become a new exhibit there.