History of Aviation(航空史)

    I. INTRODUCTION

      Aviation is defined as the design, manufacture, use, or operation of aircraft - in which the term aircraft refers to any vehicle capable of flight. Aircraft can either be heavier-than-air or lighter-than-air: lighter-than-air craft including balloons and airships, and heavier-than-air craft including airplanes, autogiros, gliders, helicopters, and ornithopters.

      For centuries man has dreamed to soar with the birds. Famous inventors such as Leonardo da Vinci, John Stringfellow, and Lawrence Hargrave have conjured up ideas of how to get some of the strangest machines to fly long before the Wright brothers' famous first flight at Kitty Hawk.

    II. EARLY AVIATION

      The first form of an aircraft was the kite, designed in the 5th century BC. Later on in the 13th century, Roger Bacon, an English monk, performed studies which later gave him the idea that air could support a craft just like water supports boats. In the 16th century, Leonardo da Vinci studied birds' flight, and later produced the airscrew and the parachute. The airscrew, leading to the propeller later on, and the parachute were tremendously important contributions to aviation. He envisioned three different types of heavier-than-air craft: the helicopter, glider, and ornithopter (a machine with mechanical wings which flap to mimic a bird). Although Leonardo's designs were impractical, seeing they required human muscular power which was insufficient to generate flight with the aircraft he envisioned, he was vital to aviation because he was the first to make scientific suggestions.

    III. THE 19TH CENTURY

      Some of the more credible developments in actual flight and stability occurred in the 19th century. British Sir George Cayley designed a combined helicopter and horizontally propelled aircraft, and British Francis Herbert Wenham used wind tunnels in his studies and predicted the application of multiple wings placed above each other. Another famous inventor was John Stringfellow, who designed a steam-engine powered aircraft which was launched from a wire. This model demonstrated lift but failed to actually climb. Lawrence Hargrave, a British-born Australian inventor, created a rigid-wing aircraft with flapping blades operated by a compressed-air motor; it flew 312 ft (95m) in 1891. A famous glider developer in the 19th century was Jean Marie Le Bris, a Frenchman who tested a glider with movable wings.

       Kites also played an important role in the development of aviation: they could be used to test aerodynamics and flight stability. Lawrence Hargrave first created the box kite in 1893, and Alexander Graham Bell developed a gigantic passenger-carrying tetrahedral-celled kite from 1895 to 1910. Some of the most important full-scale model flight attempts were made by Samuel Langley, who created the first heavier-than-air, gasoline-powered engine which actually flew. The 'aerodrome', which he called it, was powered by a 53 horsepower 5-cylinder radial engine and later crashed into the Potomac river on December 1903 -- days before the Wrights' historic flight. ()