There are many early pioneers who contributed to the development of the helicopter. The 1940s was a decade with many flying prototypes from Sikorsky, Hiller, and others. However, the first commercial helicopter certified was a Bell model 47. The design is credited to a young self-taught inventor who learned about helicopters by reading everything he could find in public libraries. His name was Arthur Young.
To test his ideas, Young set up a small aeronautical laboratory on a farm his family owned in Radnor, PA. Throughout the 1930s he experimented with many different designs and powerplants. He built so many models that crashed that he became very good at repairing them and could quickly resume flying. His biggest problem was stability. He first tried a pendulum device that could sense gravity and adjust the rotor system. It failed because any aircraft acceleration would affect the pendulum.
He finally found success with a stabilizer bar. The device used two weights on a bar mounted perpendicular to the blades, in the same plane of rotation. Acting like a gyro, it controlled cyclic pitch to keep the rotor plane fixed in space. With this system Young was able to hold extremely stable hovers with his electric-powered model.
Now that his model was flying well, he set out to interest a manufacturer in building a full-scale prototype. He was finding very little enthusiasm for his project until a friend mentioned his flying model to an engineer at Bell Aircraft Company. This led to a demonstration and a meeting with Larry Bell. Impressed with the concept, Bell gave Young a contract to build two prototypes. On November 24, 1941, Young and his new assistant, Bart Kelly, arrived at the Bell plant to start work.
After a series of political and technical issues were finally worked out, Young learned that Bell had withheld funding because of a concern about the aircraft’s ability to land safely with an engine failure. Young decided to demonstrate an autorotation with a raw egg as a passenger in his model. He started it at the top of a 30-foot ceiling and the small helicopter autorotated to the floor without breaking the egg. Bell restored the $250,000 funding and approved Young’s request for a bigger facility.
After relocating to a garage in Gardenville, NY (about 10 miles from Bell’s main plant) things started happening fast. Six months later the model 30 was ready to flight test. It was powered by a 160-hp Franklin air-cooled engine and had a 32-foot rotor diameter. Young would hover the model 30 while tethered to the ground. Many of these flights helped solve vibration issues. When it became time to release the helicopter’s tether, Bell assigned a test pilot name Floyd Carlson to the project.
After Carlson figured out how to hover the new machine, he began trying faster airspeeds. At different speeds he would encounter vibrations and Young would fix them. While flight testing continued, ship number two was being constructed. In September 1943, Carlson wrecked the helicopter when he struck the tail teaching himself autorotations. Ship number two, which had an enclosed cabin and a passenger seat, took over as the test aircraft.
In the spring of 1944 ship number one had been rebuilt and Young and his team decided to build a third prototype. The third model 30 was not authorized by Bell, but Young wanted to build it to make improvements he felt were needed. Some of these included a four-wheel landing gear, an advanced instrument panel, and a tubular tail boom.
The third model proved to be the best flying prototype, but it did not have an enclosed cabin. Young then came up with the idea of heating a large piece of Plexiglas and blowing it up like a bubble. Bell liked this model and gave Young the go ahead to produce a production prototype. On December 8, 1945, the first model 47 was completed. Shortly thereafter 10 more helicopters were built for training, product improvements, and demonstrations. Then on March 8, 1946, Bell was awarded the first commercial helicopter certification by the CAA.
The model 47 went on to star in several TV shows and movies. When production stopped in 1973, more than 5,000 versions were built.
Tags: Tim McAdams