THE AMAZING HELICOPTER!

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• published: 12 Oct 2014
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THE AMAZING HELICOPTER! The History of Helicopters 1. Historical Background 2. Stepping Stones to the Helicopter 3. The Helicopter is Born 4. The Helicopter Comes of Age Back 3. THE HELICOPTER IS BORN At the height of its popularity, Juan de la Cierva's autogyro intrigued, and amused many with its odd up and down flying antics. But there were others who were moved to more serious thoughts. These were the helicopter experimenters. Now that they had been shown one way to build a practical rotary-wing airplane, they were more convinced than ever that the aerial machine they were seeking—a craft with far greater flying ability—was possible. Instead of discouraging helicopter inventors with its near-vertical flying abilities, the autogyro spurred them on as never before. Both in Europe and America concealed in remote corners of flying fields and hangar sheds, they quietly tinkered with loving care over their mechanical brainchildren. The dream of their predecessors of a hundred years and more which they were carrying on was soon to come true. Their helicopters were as varied in style as the clouds in the sky, and all flew with differing degrees of success. They all contributed some little share toward bringing the great work to a victorious climax. Louis Damblanc, for example, built what is considered the first twin-engine helicopter. But unfortunately for this French engineer, his double-rotor aircraft crashed and was wrecked during its test flight. In Holland a quietly working aviation expert, Dr. A. G. von Baumhauer, built a machine with a single large lifting rotor and a smaller tail rotor. Although the idea for this type of helicopter had already been thought of many years previously by Louis Breguet, Dr. Baumhauer's was the first airplane of that kind to be built. Appearing in 1925, it demonstrated a fair amount of flying ability before a crash also ended its career. On one occasion the inventor managed to have it rise several feet from the ground and to hover for as long as five minutes. Many years later this style of helicopter design was to be revived and was destined to make aeronautical history. But of all the unique helicopter designs to appear during the late twenties and early thirties, those of Isacco and Maitland B. Bleeker were perhaps the most unusual. Isacco had long been associated with Pescara while the latter conducted his helicopter experiments. It was through this contact that Isacco had his interest in helicopters awakened, as well as the beginning of his own ideas for their construction. He carried out much of his development work in England. The helicopter design which Isacco produced called for each of the rotor blades to have its own small motor and propeller. This eliminated the usual single large-power source for spinning the blades. With its own propelling units and controls, each of the rotating wings was in a sense converted into an individual airplane. Another and larger motor was also in the front of the airplane, but this was mainly for pulling the craft through the air. Isacco called his invention a "helicogyro" rather than a helicopter. The rotor blades were only expected to give "lifting" assistance at take-off. They were not designed to raise the machine vertically to any great height. The motor in the nose of the plane pulled it over the ground after a short run, and this created the major lift to make it airborne. The first Isacco helicopter to feature his unique rotor arrangement was a small single-seater affair. It had a two-bladed rotor, each blade forty-one feet in diameter and each having attached a miniature low-powered engine. The machine encouraged the inventor so much during its test flights (because it actually left the ground and showed a fair amount of stability and control) that he decided to build a second one in 1929. This helicogyro, a two-seater, had the same rotor arrangement but was larger in structure. The blades were forty-nine feet in diameter. This machine was sponsored by the British Air Ministry. To the disappointment of its inventor, the craft showed very little improvement over the first model. Isacco's difficulty was not in the theory behind his rotor design—in this he was far in advance of his day—but rather in his not being able to obtain more powerful miniature motors to spin the blades. Only after many long years and the advent of the jet-propulsion era were his helicopter ideas revived and made use of in a workable rotary-wing aircraft. In the United States, meanwhile, Maitland B. Bleeker had very much the same thoughts concerning helicopter design. He also equipped the rotor blades of his experimental airplane with individual propellers almost seven feet in diameter, but here the similarity with Isacco's ended. Bleeker did not power them with their own motors; instead he used a complicated mechanical system of gears and shafts extending from a single powerful motor to the propellers.