As early as the 16th-c, Leonardo da Vinci was designing flying machines based on emulating the flapping motion of birds' wings, but the vehicle which first carried people clear of the earth's surface was a hot-air balloon constructed by the Montgolfier brothers and flown on an ascent over Paris in 1783 by De Rosier and D'Arlandes. The Frenchman Charles was developing a lighter-than-air balloon (or aerostat) at about the same time, but it was 1852 before the practical problems of controlling direction of travel and coping with adverse weather were overcome by the development of the balloon into an airship by Henri Gifford.
In the intervening period, research was being conducted using models which would be recognized today as a conventional aircraft configuration and, by 1853, Sir George Cayley, the father of aeronautics, had constructed a man-carrying glider. Also during this period (1847), John Stringfellow and William Henson built a steam-powered aircraft which, although unfortunately incapable of sustained flight, had a significant influence on subsequent aircraft design.
The development of man-carrying gliders was pursued vigorously by Otto Lilienthal who, from his study of bird flight, recognized the importance of curved airfoil sections to increase the efficiency of wing surfaces. With the continuing refinement of the internal combustion engine, invented in 1876 by Nikolaus August Otto and successfully harnessed car propulsion by Karl Benz in 1885, the way was cleared for the most significant landmark in manned, powered flight. In 1903, Orville Wright took off and flew for 12 seconds in a 12-hp engined bi-plane constructed by his brother, Wilbur, in their cycle workshop. As the reliability of the structures and engines improved, the latter particularly through Lawrence Hargrave's radical rotary design, so pioneers exploited the new medium. Amongst these were Henry Farman, who made the first cross-country flight in 1908, and Louis Bleriot, who flew across the English Channel the following year.
World War 1 provided a powerful stimulus to all aspects of aeronautical research and development, and in 1919, John William Alcock and Arthur Brown crossed the Atlantic in a twin-engined Vickers Vimy bomber. This feat was followed by flights of ever-increasing range, including the overflight of the North Pole by Richard Byrd in 1927. Later pioneering flights included Charles Lindbergh's solo crossing of the Atlantic; Amelia Earhart over the Atlantic and the Pacific oceans; Amy Johnson from England to Australia, and James Mollinson to South Africa and India.
World War 2 created a similar impetus. By the end of that conflict the later marks of the Spitfire, designed by Reginald Mitchell; the Hurricane, designed by Sidney Camm; and the Messerschmitt, designed by Wilhelm Messerschmitt and Walter Rethel, were representative of the highest states of evolution of piston-engined aircraft. This war also heralded the arrival of the jet fighter: in 1939 the Heinkel HE 178, built by Ernst Heinkel, became the world's first jet aircraft. It was followed less than two years later by the Gloster E 28/39 powered by a jet engine designed by Frank Whittle.
Rocket-powered aircraft had been introduced into limited service by the Luftwaffe during the later stages of the war, and research was continued by the USA. In 1947, Charles (Chuck) Yeager flew a Bell X-1 rocket-powered research aircraft to become the first man to fly faster than the speed of sound, breaking the so-called sound barrier. This marked a significant advance in aeronautical engineering.
The considerable use of long-range bomber aircraft during the war led directly to the development of passenger-carrying aircraft, and to the rapid growth of international air travel. By 1968 the world's first supersonic airliner, the Tupolev TU-144, had flown; followed a little later by the Anglo-French Concorde. The latter has remained in scheduled service. Its normal cruising speed is twice that of sound.
Among other significant developments have been Sidney Camm's Harrier, (the first Vertical-Take-Off-and-Landing [VTOL] aircraft successfully to enter service); and the incorporation on some aircraft, notably the General Aerodynamics F-111 fighter/bomber and the BAC Tornado, of swing wings. This concept, first conceived by Barnes Wallis, enables the angle of sweep-back of the wings to be varied in flight, in order to optimize aerodynamic efficiency during the various stages of flight.
With some military aircraft capable of reaching and operating on the fringes of space, the distinction between aeronautics and astronautics is becoming increasingly blurred. Indeed, future developments will probably draw on both sciences. The concept of aircraft taking off from normal airfields and climbing to achieve earth orbit before re-entering the atmosphere prior to a conventional aircraft-style approach and landing has already been explored by British Aerospace in their Horizontal-Take-Off-and-Landing (HOTOL) project.
