Boeing Model 307 Stratoliner

The Boeing 307 Stratoliner was the world’s first airliner to have a pressurized passenger cabin. This meant that it couId fly in the cloudless blue of the stratosphere, high above the turbulent weather that had previously so often made flight a trying experience for passengers.
The 307 was created as a spin-off of Boeing’s top military project, the development of which would become the B-17 Flying Fortress bomber. Boeing combined the bomber’s wings, tail, and powerplant with an all-new, fatter fuselage. The engines had turbo-
superchargers to make them efficient for cruising at high altitude, giving the aircraft a substantial speed advantage over the Douglas DC-3, which was dominant in the US airliner market at the time.
The first 307 was unfortunately destroyed during a test flight in March 1939, but in 1940 three Stratoliners were delivered to Pan American and four to TWA. In the years preceding the United States’ entry into World War II, the Stratoliners were heavily used;
the TWA fleet flew 4,522.500 accident-free miles. During the war they were employed as military transports, but by the time peace
returned newer airliners had left I he 307 far behind. One Stratoliner had been sold to millionaire Howard Hughes in 1939 for his personal use; it was later converted into a houseboat at Fort Lauderdale, Florida.