NASA
Men stand in front of turning vanes inside the Altitude Wind Tunnel (AWT) at the National Advisory Committee for Aeronautics Aircraft Engine Research Laboratory in this February 1944 publicity photo. The photo was taken just weeks after the tunnel became operational.
The AWT was the only wind tunnel capable of testing full-size aircraft engines in simulated altitude conditions. A large wooden drive fan, located on the other side of these vanes, created wind speeds up to 500 miles per hour.