In the mid-1940s, Boeing engineers conducted research to become familiar with gas turbines, but it became apparent that the research engines were significant in themselves. First engine run was the 667 N (150 lb) thrust Model 500 turbojet, closely followed by the 119 kw (160 shp) Model 502 turboprop. Because no applications materialized for the turbojet, efforts were focused on the Model 502, initially developed as a turboprop and later as the more widely used turboshaft engine, first delivered in 1949.
In late-1951, a Model 502 powered Kaman K-225 helicopter became the world's first gas turbine-powered helicopter, and, in late-1952, a Model 502 powered Cessna XL-19B Bird Dog became the world's first turboprop-powered light aircraft.
By the mid-1960s, significant power and reliability improvements produced the Model 502-10VC, the first U.S. turbine engine in the 149 to 224 kw (200 to 300 shp) range to receive an approved 150-hour qualification. This artifact powered the Gyrodyne QH-50C (DSN-3) drone helicopter.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.