The Prehistory Of Powered Flight - An Overview

The Prehistory of Powered Flight - An Overview From the earliest days, humans have dreamed of flying and have attempted to achieve it. Greek and Roman mythology have examples of gods who were gifted with flight. Daedalus and Icarus flew through the air, and Icarus died when he flew too close to the sun. Religions relate stories of chariots that fly through the air and winged angels that join humans with the heavens. Flying creatures that were half human and half beast appear in legends. Birds and fantastic winged creatures pulled boats and other vehicles through the air. The ancient Chinese invented spinning toys that were the earliest helicopters, and their designs may have influenced Leonardo da Vinci, one of the world's greatest inventors, artists, and visionaries. Chinese records also speak of human attempts to sail through the air by attaching themselves to kites—one of the most significant inventions leading to flight which, with its inclined wing, evolved into the airfoil. Leonardo discovered and analyzed several of the basic principles of aerodynamics and physics and designed machines (but, in most cases, did not fly them) that applied these principles. He wrote prolifically, and it was only because his written works were lost for centuries that his influence on other inventors was not greater than it was. His writings included hundred of sketches that illustrated his observations of flight in nature and the inventions he designed. He wrote and drew on key problems of aeronautics, including action and reaction; the structure of wings, carrying surfaces, and landing gear; and even devices for directional control. Others in the next centuries took tentative steps toward flight. Various individuals tried to imitate the motion of birds and built apparatus with flapping wings called ornithopters. Sometimes they attached wings to their arms and sometimes also their legs. Some mounted winged devices that they manipulated in various ways and occasionally added foot-pedal power. Although a few were able to travel short distances, others died when they jumped off roofs or towers and they and their devices crashed to the ground. Other experimenters tried gliding rather than flapping. In general, these were more successful than the flapping efforts, although the distances were still very short. In any case, many claimed to have flown but, not surprisingly, few had witnesses or could offer proof. The first experimenter who actually analyzed the various forces that contributed to flight was the Englishman George Cayley at the end of the eighteenth century. Cayley identified and defined the forces of flight and sketched out an airplane that had the primary elements of a modern aircraft. Cayley defined the principles of mechanical flight and stated that, to fly, it was necessary for surfaces to be able to support a weight by applying "power to the resistance of air." In other words, the force that moved an object in a forward direction had to be greater than the opposite force (resistance or drag) that the air exerted on an object. His "On Aerial Navigation" was one of the important early works on aviation. He also introduced the scientific method to the study of aviation—stressing careful analysis of problems and thorough testing. In the mid-nineteenth century, he demonstrated these principles with glider models that actually were able to carry the weight of a passenger a short distance. Cayley also experimented with variously shaped wings and demonstrated the importance that wing shape had on the ability of an aircraft to generate the lift that kept it afloat. Cayley's work influenced inventors for at least the next fifty years. Both unpowered gliders and planes that were powered by engines were attempted. Gliders were built that progressively could fly farther and farther and over which the pilots gradually gained control. Some of these gliders were outlandish-looking devices with various types of wing designs that had one, two, three, or even more flying surfaces. Some had short stubby wings while others had wings that were extremely long and narrow. In France, the founding of the first aeronautical society, the Soci‚te A‚rostatique et M‚t‚orologique de France, in

1852, marked the recognition of aviation as a legitimate discipline. Louis Charles Letur built and tested a parachute-glider, which was the first pilot-controlled machine to be tested in flight. Michel Loup, Jean-Marie LeBris, and others built flying machines that were modeled after birds. Inventors added engines to their gliders or balloons to provide forward motion as they became available or built new designs that were meant to use the power provided by an engine. The first engines were steam-driven and generally were too heavy to provide enough power for effective lift in relation to their weight of the apparatus they were meant to power. In England, William Henson designed and patented the Aerial Steam Carriage, a powered device that was based on Cayley's doctrines. It was never built, but the steam engine that was designed to power it was judged the best that had been built up to that time. However, inventors had more success when an engine was used with a balloon. The year 1852 marked the first time a powered device had been applied to an airframe—in this case, it was Henri Giffard's airship that was driven by a three-horsepower steam engine. Two decades later, F‚lix Du Temple built a steam-powered monoplane that managed to rise a few feet off the ground—the first powered fixed-wing aircraft that carried a passenger, albeit down a slope. Thomas Moy built an Aerial Steam Carriage that was a monoplane powered by a steam engine that lifted a few inches off the ground. These aircraft displayed various types of propeller assemblies that were all sizes. Other inventors, such as Alphonse Pénaud, used twisted rubber strips, basically a rubber band, to propel their flying machines. He developed theories about wing contours that he successfully applied to model airplanes, helicopters, and ornithopters. He also designed an amphibian monoplane that anticipated features that were implemented later. But he committed suicide before the design took real shape. Others used compressed air to generate thrust, and one inventor used gunpowder to power a propeller. Others reshaped wing to make them more aerodynamically effective and generate more lift. The final advances before the achievements of the Wright brothers took place in Europe in the last decade of the nineteenth century. The first was that of the French Cl‚ment Ader who flew one machine more than 150 feet (50 meters) but only inches off the ground and a second about ten feet (three meters) off the ground. He claimed he was the first to fly, but others categorized his achievements as mere "hops." The second, and more significant development, was that of the German engineer Otto Lilienthal, who was the first to launch himself into the air and fly. He built monoplane, biplane, and triplane gliders--eighteen variations in all--and conducted experiment after experiment that tested their flying abilities. He earned the title the "father of aerial testing" with his more than two thousand glider flights, some which covered distances of over a thousand feet (300 meters) before he died as a result of a crash landing in 1896. The American Octave Chanute also was a major figure at the end of the nineteenth and beginning of the twentieth centuries. Chanute, a respected and successful engineer and bridge builder, documented the efforts of others who had experimented with aviation, whether they had been successful or were abject failures. He was the first aviation historian and lent his considerable reputation and analytical skills to publicizing and adding respectability to the burgeoning discipline. He also constructed and flew gliders with his colleague Augustus Herring along the shores of Lake Michigan near Chicago, Illinois. Chanute served as a friend and mentor to the Wright brothers and encouraged them in their efforts. The final unsuccessful attempt at powered flight occurred in the United States. Samuel Pierpont Langley, astronomer and secretary of the Smithsonian Institution in Washington, tested several small models that were powered by gasoline engines. These were successful

and he was encouraged to try a full-size plane called an Aerodrome. He attempted two launches in 1903, just days before the Wright brothers made their first powered flight, from a houseboat anchored in the Potomac River near Washington, D.C. Both attempts were unsuccessful. --Judy Rumerman