General Electric T31

The General Electric T31, which the company designated TG-100A, was the first turboprop engine designed and built in the United States. It benefited from the Anglo-American technology exchange, one of its designers, Glenn Warren, stating that the most important British contribution was the concept of multiple combustion cans, and its axial compressor design was directly influenced by the NACA eight-stage compressor. General Electric chose a single-shaft layout like the Rolls-Royce Dart, with a 14-stage all-axial compressor, a single stage turbine and a long epicyclic propeller reduction gearbox. The XT31 was first used in the experimental Consolidated Vultee XP-81, which first flew on 21 December 1945 as the first aircraft to combine turboprop and turbojet power, with an Allison J33 turbojet in the rear fuselage.