Flown for the first time in the summer of 1955, the second 43-seat Piasecki PV-15 (U.S.A.F: 50-1270) is powered by two 2.925-e.s.h.p. Allison T-38-A-6 shaft turbines. Called the YH-16A Turbo-Transporter, this tandem-rotor helicopter can carry three Jeeps or four tons of cargo. The first PV-15 (50-1269) is being re-engined - formerly two P. & W. Twin Wasp R-2180-11 radials - to become the YH-16B, with two 3.750-e.s.h.p. Allison T56-A shaft turbines.