A new use for the U.S. Navy airship as a "flying wind tunnel" has solved?
A new use for the U.S. Navy airship as a "flying wind tunnel" has solved the frustrating problem on testing models of vertical rising and short take-off and lending (VTOL/STOL) aircraft.
The basic problem in developing VTOL/STOL machines is that there is
that there is a negligible amount of data available on low speed aerodynamics due to the difficulty in using standard with tunnels for this purpose. Large, powered models need to be used to test these types of aircraft, and there are few wind tunnels large enough to accommodate them. Those that exist are not generally designed to simulate low speeds, and attempt to modify them have proved unsatisfactory. Also the more complex configurations of VTOL/STOL cause severe disturbances in present tunnels.
An exploratory programme was instituted with the cooperation of the Airship Test and Development Department at the U.S. Naval Air Station, Lakehurst, New Jersey, using the 285-foot Z82G-1 airship. This provided the feasibility of testing VTOL models for control and stability by hanging them beneath the car (gondola) on a retractable strut.
The larger ZPG-2, which is 343 feet long and has a considerably larger car and a ceiling of 5000 feet, has now been assigned to the programme. This airship can remain stable in flight at zero airspeed in an equilibrium condition with no perceptible pitching, rolling, or yawing. Velocities from zero to 15 knots can be held for approximately a half-hour, which is adequate for currently conceived tests. Airspeeds from 15 to over 60 knots can be maintained indefinitely as a constant altitude. The ZPG-2 airship as a flying wind tunnel has been shown to give accurate, repeatable data for a variety of configurations with no difficulty.