December 03, 1999
(NASA 650) was a G-II modified for the joint NASA/ Lockheed Propfan Test Assessment program. The aircraft was fitted with a turboprop engine driving a "propfan" on the left wing only; a thick shield was applied to the side of the fuselage nearest the fan blades for protection. Also of interest are the long instrumentation boom and small counterweight on the left wing, and the much larger counterweight on the right wing, for balance purposes. The PTA program ran for about a year.