|Dryden Home > Collections > Photo Home > PA-30 Twin Comanche|
After being purchased in 1967, NASA 808 was used as a testbed for general aviation flight control research. NASA's first project with the aircraft was the determination of its stability and control characterisitics in the Langley full-scale wind tunnel. The wind tunnel measurements were then correlated with in-flight measurements of the stability and control characteristics at Dryden. This was the first time full-scale wind tunnel measurements of a general aviation aircraft had been made since the late 1930s. As a result of the studies, several changes were made by the contractor to the aircraft to improve its flying qualities. These changes are manifested in later models of the airplane.
Another project involving general aviation was the PA-30 program to define the operating techniques necessary to enable curved landing approaches as a part of routine operation at major airports. The program, in support of NASA's Short Take Off and Landing (STOL) project, was designed to facilitate large and small, STOL and conventional aircraft using the same runway.
In the early 1970s, the PA-30, serial number 30-1498, was used to test a flight technique used to fly Remotely Piloted Research Vehicles (RPRV's). The technique was first tested with the cockpit windows of the light aircraft blacked out while the pilot flew the aircraft utilizing a television monitor which gave him a "pilot's eye" view ahead of the aircraft. Later pilots flew the aircraft from a ground cockpit, a procedure used with all RPRV's. TV and two-way telemetry allow the pilot to be in constant control of the aircraft. The apparatus mounted over the cockpit is a special fish eye lens camera, used to obtain images that are transmitted to the ground based cockpit. This project paved the way for sophisticated, highly successful research programs involving high risk spin, stall, and flight control conditions, such as the HiMAT and the subscale F-15 remotely piloted vehicles.
Over the years, NASA 808 has also been used for spin and stall research related to general aviation aircraft and also research to alleviate wake vortices behind large jetliners.
In November 1973, the PA-30 and an F-104 were used to measure the force and effects of wake vortices behind large aircraft using a three engine B-727. Smoke generators were placed on the 727 and the smaller aircraft followed to measure the vortices. This program directly influenced the later wake vortex tests on NASA's 747 using a T-37B and a Learjet as chase aircraft, which led to successful means of alleviating dangerous vortices.