Boeing C-97 Stratofreighter - Design and Development

Design and Development

The Boeing C-97 Stratofreighter was developed towards the end of World War II by fitting an enlarged upper fuselage onto a lower fuselage and wings which were essentially the same as those of the B-50 Superfortress with the tail, wing, and engine layout being nearly identical. It was built before the death of president of Boeing, Philip G. Johnson. It can be easily distinguished from the 377 Stratocruiser airliner by the radar "beak" radome beneath the nose, and by the flying boom and jets on later tanker models.

The prototype XC-97 was powered by the 2,200hp (1,640kW) Wright R-3350 engine, the same as used in the B-29. This aircraft and the other pre-production examples were fitted with a shorter fin and rudder than used subsequently. The C-97 had clamshell doors under its tail, so a retractable ramp could be used to drive in cargo. But unlike the later Lockheed C-130 Hercules, it was not designed as a combat transport which could deliver directly to primitive forward bases using relatively short takeoffs and landings. The rear ramp could not be used in flight for air drops.

On 9 January 1945, the first prototype, piloted by Major Curtin L. Reinhardt, flew from Seattle to Washington, DC in 6hours 4 minutes, an average speed of 383mph (616km/h) with 20,000 pounds (lb) of cargo, which was for its time rather impressive for such a large aircraft. Production models featured the 3,500hp (2,610kW) Pratt & Whitney Wasp Major engine, the same engine as for the B-50.

The C-97 had a useful payload of 35,000lb (16t) and could carry two normal trucks, towed artillery, or light tracked vehicles such as the M56 Scorpion. The C-97 was also the first mass-produced air transport to feature cabin pressurization, which made long range missions somewhat more comfortable for its crew and passengers.