Cleveland's Glenn Research Center began as the Aircraft Engine Research Laboratory of the National Advisory Committee for Aeronautics (NASA's predecessor). The Altitude Wind Tunnel, built in 1944, could run at 250-425 mph at simulated altitudes of 1000-30,000 feet. It was the only known wind tunnel specifically designed to test aircraft engines at such conditions. Tests in the tunnel assisted in solving engine-cooling problems for the B-29 bomber plane of World War II. The first wind tunnel tests on American jet engine prototypes were conducted here. The vertical structures shown are "turning vanes" added on the downstream surface to straighten the flow through an elbow of the tunnel that is no longer in service.