Boeing XC-97 Sets a Transcontinental Speed Record

In 1945 the Boeing XC-97 prototype set a notable transcontinental speed record, flying from Seattle, Washington, to Washington, D.C. in just over six hours. The big transport averaged nearly 400 miles per hour on the run, a striking pace for a cargo aircraft of its day.

The XC-97 was developed from the B-29 Superfortress, marrying the bomber's wings, tail, and engines to an enlarged, double-bubble fuselage that gave it a far greater cargo and passenger volume. Like the B-29, it was fully pressurized, allowing it to cruise efficiently at high altitude.

The design matured into the C-97 Stratofreighter and its KC-97 tanker variant, which served the Air Force for years, while the same airframe concept produced the Boeing 377 Stratocruiser airliner. The aircraft thus formed an important bridge between wartime bomber technology and the postwar generation of large pressurized transports.