Airplane modifier Texas Turbine Conversions has begun flight testing of its conversion of the de Havilland DHC-3 Otter. The modification includes the replacement of the original 600 hp, nine cylinder Pratt & Whitney radial with an AlliedSignal/Garrett TPE331 10 turboprop engine flat rated to 900 horsepower. While the airframe is limited to a 125 knot airspeed, the additional power helps the Otter climb better and fly at max speeds to much higher altitudes than it could with the radial. The engine swap saves 400 pounds, which translates into a better useful load, and gives operators a greatly increased TBO up to 5,400 hours over the P&W radial.
All Aero 