General Electric T31 / TG-100
The first American turboprop engine was the General Electric XT31, first used in the experimental Consolidated Vultee XP-81. The XP-81 first flew in December 1945, the first aircraft to use a combination of turboprop and turbojet power.
The T31 engine was the first American turboprop engine to power an aircraft. First run in May 1945, it made its initial flight in the Consolidated Vultee XP-81 on 21 December 1945. The T31 was mounted in the nose; a J33 turbojet engine mounted in the rear fuselage provided added thrust. The T31 was also used on the Navy XF2R-1, similarly powered by a turboprop/turbojet engine combination.
The engine was to have been flown experimentally on a Curtiss XC-113 (a converted C-46), but the experiment was abandoned after the XC-113 was involved in a ground accident. Only 28 T31s were built; none were used in production aircraft, but improved production turboprop engines were developed from the technology pioneered by the T31.
A derivative of the T31, the General Electric TG-110, given the military designation T41, was ordered but subsequently cancelled.