Undated (AP) _ Facts about the Lockheed Aeronautical Systems Co. High Technology Test Bed, which crashed Wednesday at Dobbins Air Force Base:

-Developed in 1984, HTTB that crashed was the only one in existence.

-Plane is modified version of C-130 Hercules Transport, a large cargo plane widely used by military.

-Known as a ''flying laboratory,'' the plane was equipped with advanced data-gathering equipment used to test new technologies: short takeoff and landing, survivability, electronic systems, cockpit displays and precision navigation.

-Designed to fly at much lower-than-normal speeds, mainly to test short- distance landing.

-HTTB was used mainly by Lockheed but was available to government agencies, universities and other companies for technology tests.