13 September 1935: Flying his Hughes H-1 Special, NR258Y, Howard Robard Hughes, Jr. set a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a 3 Kilometer Course near Santa Ana, California. Making four passes over the measured course, two in each direction, his average speed was 567.12 kilometers per hour (352.39 miles per hour).¹ This was 61.27 kilometers per hour (38.07 miles per hour) faster than the previous record which had been set by Raymond Delmotte, 24 December 1934.
Just after completing the final pass over the course, the airplane’s engine stopped due to fuel starvation. Hughes made a belly landing in a farm field. He was uninjured and the airplane received only minor damage.
The Hughes H-1 (Fedral Aviation Administration records identify the airplane as the Hughes Model 1B, serial number 1) was a single-seat, single-engine low-wing monoplane with retractable landing gear. Emphasis had been placed on an aerodynamically clean design and featured flush riveting on the aluminum skin of the fuselage. The airplane was 27 feet, 0 inches long (8.230 meters) with a wingspan of 25 feet (7.6 meters) and height of 8 feet (2.438 meters). (A second set of wings with a span of 31 feet, 9 inches (9.677 meters) was used on Hughes’ transcontinental flight, 19 January 1937). The H-1 has an empty weight of 3,565 pounds (1,617 kilograms) and gross weight of 5,492 pounds (2,491 kilograms).
The H-1 was powered by a air-cooled, supercharged 1,534.943-cubic-inch-displacement (25.153 liter) Pratt & Whitney Twin Wasp Jr. two-row, fourteen-cylinder radial engine. Pratt & Whitney produced 18 civil and 22 military (R-1535) versions of the Twin Wasp Jr., in both direct-drive and geared configurations, rated from 650 to 950 horsepower. It is not known which version powered the H-1, but various sources report that it was rated from 700 to 1,000 horsepower. The engine drove a two-bladed Hamilton Standard controllable pitch propeller.
8 December 1945: At the Bell Aircraft Corporation Wheatfield Plant, Niagara Falls, New York, the first Model 47 helicopter, NX41962, was rolled out. Designed by Arthur M. Young, the Model 47 was based on Young’s earlier Model 30. The helicopter made its first flight on the same day.
The Civil Aviation Administration (C.A.A.), predecessor of the Federal Aviation Administration, had never certified a helicopter, so Bell worked with government officials to develop civil certification standards. The Bell 47 received the C.A.A. Type Certificate H-1 on 8 March 1946 and the first helicopter’s registration was assigned changed to NC1H.
The Bell 47 series was constructed of a welded tubular steel airframe with a sheet metal cockpit and a characteristic plexiglas bubble. In the original configuration, it had a four-point wheeled landing gear, but this was soon replaced with a tubular skid arrangement. It was a two-place aircraft with dual flight controls.
The first Bell Model 47 had an overall length (with rotors turning) of 39 feet, 7½ inches (12.078 meters). The main rotor diameter was 33 feet, 7 inches (10.236 meters). The length of the fuselage, from the front of the plexiglass bubble canopy to the trailing edge of the tail rotor disc, was 29 feet, 3½ inches (8.928 meters). The tail rotor had a diameter of 5 feet, 5 inches (1.676 meters). The helicopter’s height, to the top of the main rotor mast, was 9 feet, 2-7/16 inches (2.805 meters).
NC1H had an empty weight of 1,393 pounds (632 kilograms). Its gross weight was 2,100 pounds (953 kilograms).
The Bell 47’s main rotor is a two-bladed, under-slung, semi-rigid assembly that would be a characteristic of helicopters built by Bell for decades. The blades were constructed of laminated wood, and covered with fabric. A stabilizer bar was placed below the hub and linked to the flight controls through hydraulic dampers. This made for a very stable aircraft. The main rotor turns counter-clockwise, as seen from above. (The advancing blade is on the right.) The tail rotor is positioned on the right side of the tail boom in a tractor configuration. It rotates counter-clockwise as seen from the helicopter’s left. (The advancing blade is above the axis of rotation.)
Power was supplied by an air-cooled, normally-aspirated, 333.99-cubic-inch-displacement (5.473 liter) Franklin Engine Company 6V4-175-B3 vertically-opposed six cylinder engine, serial number 17008, rated at 178 horsepower at 3,000 r.p.m. Power was sent through a centrifugal clutch to a gear reduction transmission which turned the main rotor through a two-stage planetary gear system. The transmission also drove the tail rotor drive shaft, and through a vee-belt/pulley system, a large fan to provide cooling air for the engine.
The new helicopter had a cruise speed of 75 miles per hour (121 kilometers per hour) and a maximum speed (Vne) of 80 miles per hour (129 kilometers per hour). NC1H had a service ceiling of 11,400 feet (3,475 meters).
The Bell 47 was produced at the plant in New York, and later at Fort Worth, Texas. It was steadily improved and remained in production until 1974. In military service the Model 47 was designated H-13 Sioux, (Army and Air Force), HTL (Navy) and HUG (Coast Guard). The helicopter was produced under license by Agusta, Kawasaki and Westland. More than 7,000 were built worldwide and it is believed that about 10% remain in service.
In 2010, the type certificates for all Bell 47 models was transferred to Scott’s Helicopter Service, Le Sueur, Minnesota, which continues to manufacture parts and complete helicopters.
After certification testing and demonstrations, NC1H was one of two Bell 47s used for flight training. The first Bell 47, s/n 1, crashed at Niagara Falls Airport, 3 April 1946.
While hovering out of ground effect, a student inadvertently oversped the main rotor. The main rotor hub separated and the helicopter dropped to the ground. Both the student and instructor were injured. Damage to NC1H was extensive and the helicopter was scrapped. The registration, NC1H, was reassigned to Bell 47 s/n 11.