The first of two Consolidated-Vultee XP-81 prototypes, 44-91000 became the first American turboprop-powered aircraft to fly on 21 December 1945. The TG-100 turboprop was augmented by an I-40 turbojet in the tail, fed air by dorsal intakes. Performance was disappointing as neither engine delivered the expected power and the P-81, intended as an escort fighter, was cancelled. Photo from: University of Texas at Arlington