Maneuvering aircraft may encounter a dangerous condition known as spin, caused by a sudden loss of lift over wings or control surfaces. NASA’s 20-Foot Vertical Spin Tunnel (VST) is the only operational tunnel of its kind in the Western Hemisphere that conducts free-spin research using dynamically scaled, free-flying models. The VST is a closed throat, annular-return facility that operates at nominal atmospheric conditions, with velocities that can be rapidly adjustable up to 85 ft per sec.
VST studies identify and quantify spin and spin-recovery characteristics of a given vehicle configuration. Related tumbling research identifies susceptibility to out-of-control pitch autorotation and strategies for safe recovery. Forced-oscillation capability has recently been added to the tunnel’s rotary balance in order to measure body-axis rate-damping characteristics.
The VST has supported the development of nearly all U.S. military fighter and attack airplanes, trainers and bombers, as well as some foreign designs. It is the only resource available to commercial aircraft manufacturers for proprietary spin-and-tumble assessments of their products in a wind tunnel environment.
