Tag Archives: Lycoming T53-L-11

27 September 1964

Captain Michael N. Antoniou with YUH-1D 60-6029. (FAI)

27 September 1964: Captain Michael N. Antoniou flew the number two Bell YUH-1D-BF Iroquois, 60-6029, Bell Helicopter serial number 702, from Edwards Air Force Base in the high desert of southern California, non-stop to Rogers, Arkansas. The distance flown was 2,170.70 kilometers (1,348.81 miles), and established a Fédération Aéronautique Internationale (FAI) World Record for Distance Without Landing.¹

Captain Antoniou was a project test pilot assigned to the U.S. Army Aviation Test Activity at Edwards.

60-6029 was modified by Bell to reduce aerodynamic drag and weight. The windshield wipers, door handles, main rotor stabilizer bar and associated dampers, tail rotor drive shaft cover and 42° gear box cover had been removed. Gaps at the doors, crew steps, tail boom cargo compartment, etc., were sealed with tape.

Bell YUH-1D Iroquois 60-6029. (FAI)

The Bell Helicopter Co. UH-1D Iroquois (Model 205) was an improved variant the UH-1B (Model 204). The type’s initial military designation was HU-1, and this resulted in the helicopter being universally known as the “Huey.” The UH-1D has a larger passenger cabin, longer tail boom and increased main rotor diameter.

The UH-1D was a single main rotor/tail rotor medium helicopter powered by a turboshaft engine. It could be flown by a single pilot, but was commonly flown by two pilots in military service. The helicopter had an overall length of 57 feet, 0.67 inches (17.375 meters) with rotors turning. The fuselage was 41 feet, 5 inches (12.624 meters) long. The helicopter had a height of 13 feet, 7.4 inches (4.150 meters), measured to the top of the mast. The maximum gross weight of the UH-1D was 9,500 pounds (4,309.1 kilograms).

The two blade semi-rigid, under-slung main rotor had a diameter of 48 feet, 3.2 inches (14.712 meters), and turned counter clockwise when viewed from above. (The advancing blade is on the helicopter’s right.) At 100% NR, the main rotor turned 324 r.p.m. The two blade tail rotor assembly had a diameter of 8 feet, 6 inches (2.591 meters). It was on the left side of the pylon in a pusher configuration and turned counter-clockwise as seen from the helicopter’s left. (The advancing blade is above the axis of rotation.)

The YUH-1D was powered by a Lycoming T53-L-9 or -11 turboshaft engine which was rated at 1,100 shaft horsepower at 6,610 r.p.m., for takeoff (5 minute limit). The T53-L-11 was a two-shaft free turbine with a 6-stage compressor (5 axial-flow stages, 1 centrifugal-flow stage) and a 2-stage axial-flow turbine (1 high-pressure stage, and 1 low-pressure power turbine stage). As installed in the UH-1, the engine produced 115 pounds of jet thrust (511.55 Newtons) at Military Power.

Its maximum speed, VNE, was 124 knots (143 miles per hour, 230 kilometers per hour). With full fuel, 206.5 gallons (781.7 liters), the helicopter had a maximum endurance of three hours.

60-6029 was later modified to the prototype YUH-1H.

Captain Michael N. Antoniou with Bell YUH-1D-BF 60-6029 (c/n 702), circa 1965. (David Hatcher Collection)

¹ FAI Record File Number 2180

© 2018, Bryan R. Swopes