Aircraft | Research & Encyclopedia Articles

Aircraft

The human fascination with flight is older than recorded history. An ancient Chinese legend tells of a prince who builds a wind-powered flying chariot, and in the famed Greek myth, Daedalus devises wings of feathers and wax so he and his son Icarus can escape their island prison. Icarus flies too close to the sun, his wings melt, and he plunges to his death.

Early history records a number of other failed attempts at imitating the flight of birds. Over nine hundred years ago, in what surely must have been a leap of faith, an English monk with a wing attached to each arm jumped off a church roof; somewhat remarkably, he suffered only two broken legs. A Frenchman attempting a similar feat some four centuries later was not so lucky; he fell to his death from a high church steeple. Around 1500, Leonardo da Vinci was busily observing birds in flight and sketching designs for flying machines that employed flapping wings; he even made some models. Wisely, given the fate of others before him, he did not attempt to use them.

It could be said that the Chinese were the first to successfully put human beings in the air. In the 1200s, they were using manned kites not only for reconnaissance during wartime but also as punishment for criminals. But kites are tethered to the ground, and so the dream of a human being flying as free as a bird was still not realized, nor would it be until 1783.

The first successful free flight of human beings relied not on wings but on the fact that hot air is lighter than cool air. In France in the early 1780s, Joseph-Michel Montgolfier and Jacques-Étienne Montgolfier, sons of a wealthy paper manufacturer, noticed that bags grew lighter and lifted into the air when held above a fire. In November 1783, after a series of experiments, the Montgolfiers successfully launched a hot-air balloon containing two human beings--the first manned aircraft. Other enthusiasts, such as the French physicist Jacques Charles, began filling balloons with hydrogen--a gas lighter than air--to create buoyancy. This procedure not only eliminated the necessity of keeping a fire burning beneath the craft; it also meant that the balloon did not sink as the hot air within it cooled.

Balloons were still dependent on the wind for direction, and by 1852, the desire for better control had led Henri Giffard to design a balloon that had a propeller driven by a steam engine. Known as a dirigible, or airship (as engine-powered lighter-than-air craft came to be called), it was perfected by Ferdinand von Zeppelin in Germany in the late nineteenth century. Zeppelin's design, based on David Schwarz's, used an enormous metal frame with a cloth skin stretched over it. The hydrogen-filled zeppelins could be steered with complete control and by 1914 had transported more than 10,000 passengers.

Despite the success of balloons and airships, winged flight never lost its allure. As early as 1804, an Englishman by the name of George Cayley had built a small, operable winged glider. He wanted to use some kind of power to run a propeller, but no suitable engine was then available. By the 1890s, Otto Lilienthal of Germany had made over two thousand glider flights, sometimes traveling over 700 feet (213.5 m). His goal, too, was to motorize a glider, but he died in a crash before he could attempt it.

An American, Octave Chanute, improved on Lilienthal's glider design by placing another set of wings above the lower ones, thus creating a biplane. Although some would-be aviators in the nineteenth century did succeed in attaching steam engines to aircraft, their machines produced only uncontrolled jumps. Even with a head start down a ramp in 1874, Frenchman Felix Du Temple's steam-powered craft stayed airborne for only two seconds. In 1884, a similar attempt by a Russian, Alexander Mozhaiski, had similar results. In 1890, a French engineer, Clement Ader, managed a precarious hop of 150 feet (46 km), but he had no control of the flight and could not stay aloft. Hiram Maxim, a prolific American-born inventor, somehow managed to get his 3.5 ton (3.2 t) biplane off the ground for a few seconds in 1894.

But Samuel Langley, an American scientist, had the most promising early results. His unmanned Aerodrome flew half a mile (.8045 km) in ninety seconds in 1896, but he could not follow up with a piloted flight.

The triumph of the first controlled and sustained flight in engine-powered, heavier-than-air craft belongs to the Americans Orville and Wilbur Wright. Using knowledge gained by the early glider pioneers and their own engineering skill, they constructed a steerable biplane with a gasoline engine and two propellers. Orville flew it for the first time for 120 feet (37 m) in 1903, and by 1905 the Wright brothers were making flights of more than 20 miles (32 km).

A number of other firsts quickly followed the Wrights' exploits. In 1906, Alberto Santos-Dumont, a Brazilian, became the first man to fly a plane in Europe. In 1908, Henri Farman, an Englishman living in France, flew almost 17 miles (27 km) directly across the French countryside and because the Wright brothers' flights were circular, made the world's first long-distance cross-country flight.

In 1909, a London newspaper offered a reward to the first person who could cross the English Channel in an airplane. A daring Frenchman, Louis Blériot, took the challenge and completed his rough flight from France to England in thirty-seven minutes. Three years later, Harriet Quimby, an American, became the first woman to fly across the channel. Other innovations during these years included Henri Fabre's seaplane with floats for landing and Armand Deperdussin's sleek, single-winged plane, which in 1912 became the first craft to fly over 100 miles (161 km) per hour.

World War I (1914-1918) created a demand for a different kind of aircraft. At first, planes were used only for scouting out enemy positions, but it wasn't long before machine guns were being mounted on the front of planes to rid the skies of enemy craft. The problem in the ensuing dogfights was that the pilot, who was also the gunner, was as likely to hit his own propeller as he was an enemy plane. One solution on the Allied side was to attach steel deflector plates to the propeller. But Anthony Fokker gave the Germans a better system by designing an interrupter gear that prevented the machine gun from firing when the propeller blade was in front of the gun muzzle.

By 1916, many French and British planes were using a revolutionary engine: the rotary, which unlike conventional engines, had a stationary crankshaft around which the cylinders and crankcase rotated with the propeller bolted to their front. The rotary had both power and mechanical simplicity. The increased torque (or tendency to twist) that it produced allowed experienced pilots to turn abruptly, an advantage in dogfights.

The typical plane at the start of the war was a biplane that could fly 60 to 70 miles (97 to 113 km) per hour. By 1918, planes were stronger, more maneuverable, and capable of speeds in excess of 130 miles (209 km) per hour. Hugo Junkers of Germany had introduced the Junkers J-1, the first all-metal plane with cantilevered wings (i.e., wings supported by the body of the plane rather than by outside bracing). World War I also produced the first aerial bomber plane s, which carried out raids over London, Paris, and several German cities. Zeppelins, too, were put into service as bombers and created havoc during their dozen attacks on London. Ultimately, however, the aircraft of this time were ineffective as weapons of war. No airplane or airship ever managed to sink or even seriously damage a warship, nor were any land battles decided mainly on the basis of air power.

When World War I ended, enthusiasm for flying was high. Many former air force pilots found an outlet for their passion in barnstorming--performing dramatic, risky stunts at state fairs and carnivals. Others set out to break distance or endurance records, such as crossing the Atlantic nonstop. In 1919, two British airmen, Alcock and Brown, took off from Newfoundland in a bomber and headed for Europe. The weather was so terrible they had to take turns crawling out on the wings to chip the ice away; after sixteen hours of flying, they landed in Ireland. In 1926, two Americans, Floyd Bennett and the explorer Richard Byrd, became the first people to fly over the North Pole.

The most celebrated feat of the era was the first solo crossing of the Atlantic Ocean by Charles Lindbergh, a mail pilot, in 1927. Using an extra fuel tank on his specially rebuilt plane, The Spirit of St. Louis, Lindbergh flew without a radio or parachute from New York to Paris in just under 34 hours. Four years later, Hugh Herndon and Clyde Pangborn completed the first nonstop flight across the Pacific. And a year after that, in 1932, Amelia Earhart became the first woman to cross the Atlantic solo, only to disappear over the Pacific five years later as she attempted to circle the globe. By 1933, Wiley Post had made the first solo flight around the world; with eleven stops, it took him seven days and eight hours. In 1938, Howard Hughes reduced the time for a transworld flight to three days and nineteen hours.

The sale of surplus military planes after the war helped bolster the enthusiasm for flight. Just before 1920, the world's first scheduled airlines went into business, many of them using rebuilt military craft on runs between European cities. They had plenty of competition from airships. By 1929, a huge German airship, the Graf Zeppelin, had flown around the world in just over twenty-one days, and airships were making regular runs across the Atlantic. Many believed these craft would always be the best means of air travel. However, the dramatic explosion of the Hindenburg over New Jersey in 1937, which killed thirty-six people aboard, put an end to the use of airships as passenger craft.

Heavier-than-air craft improved significantly during the 1920s and 1930s. Planes became larger, stronger, and faster, achieving speeds of over 300 miles (483 km) per hour, and workhorse planes, such as the all-metal Douglas DC-3, began providing reliable transport for cargo and passengers.

Helicopters, craft that can take off and land vertically and hover in mid-air, also came into their own at this time. Although the idea of vertical flight goes at least as far back as Leonardo da Vinci, the technical difficulties involved were not overcome until the late 1930s, when Heinrich Focke built a two-rotor helicopter and Igor Sikorsky built the first workable single-rotor machine. Helicopters were well on their way to useful service by 1940.

At the start of World War II (1939-1945), many countries still used biplanes that performed little better than those used in the earlier war. Germany held the technological lead with excellent fighter planes like the Messerschmidt Bf 109, an all-metal monoplane with one to three cannons and two machine guns, and good twin-engine bombers like the Junkers Ju-88. The Japanese also began the war with a superior fighter, the Zero. As the war progressed, the United States and Britain produced aircraft that matched and then surpassed the enemy planes they met in battle. By the last year of the war, the United States' Boeing B-29 Superfortress, an immense bomber, had made its predecessors obsolete. It could fly for distances of 5,000 miles (8,045 km) carrying enormous loads of bombs. It was a B-29 bomber that dropped the atomic bomb at Hiroshima.

Perhaps the most important technological advance of World War II was the development of jet engines for aircraft. Rather than using fuel to turn a propeller, jet engines mix fuel and air in a combustion chamber, igniting it and blowing it out of the engine as high-speed exhaust. This creates an immense thrust forward. Both the Allied and Axis scientists knew that these engines would make airplanes capable of speeds from 500 to 600 miles (804.5 to 965 km) per hour, and so a frenzied race to develop them began.

In 1939, a jet engine developed by the German Hans von Ohain was tested on a Heinkel plane, and the Allies scrambled to match this advance. In 1941, the jet engine developed by the British scientist Frank Whittle successfully propelled a plane at speeds matching the best British fighter then in use. The Americans quickly borrowed Whittle's technology, hoping to create their own jet engines. But the more immediate need for conventional planes precluded the introduction of jets by either the Axis or the Allies, and by the time Germany introduced its awesome jet-powered Messerschmidt Me-262 late in 1944, the outcome of the war was already decided.

The jet opened new frontiers for aviation. Scientists and fliers could now turn their attention to the challenge of breaking the sound barrier. Though some German rocket-powered planes had exceeded 600 miles (965 km) per hour, many felt that would be the absolute speed limit, because at speeds approaching 740 miles (1,191 km) per hour--the speed of sound--air piled up in front of a plane, threatening to shake it apart if the pilot tried to push through the resistance. In the United States, Bell Aircraft built the X-1, an experimental plane with thin wings and tail designed to slice through the air smoothly, and four powerful rocket engines to drive the plane through piled-up air. In October 1947, a B-29 carried the X-1 and its pilot, Chuck Yeager, to 30,000 feet (9,150 m), where the plane was released, and Yeager ignited his rocket engines. With only a little shaking, Yeager reached Mach 1, the speed of sound, and those on the ground heard the first sonic boom, resulting from a shock wave produced by the world's first supersonic plane.

With the sound barrier broken, new speed records were made regularly. By the 1960s, the American-made experimental X-15 had traveled at the speed of Mach 5, equal to five times the speed of sound. It had also flown to an amazing altitude of 50 miles (80 km), qualifying it as the first airplane that was also a spacecraft.

Highly efficient jet engines came into wide use during the Korean War (1950-1953), powering the first successful jet fighters. The jet technology developed for military use was also applied to civilian transport and in the 1950s began supplanting propeller-driven systems on commercial and passenger craft.

The first passenger jet, Britain's De Havilland Comet, made its debut in 1952, carrying passengers at 500 miles (804 km) per hour. The Boeing 707 introduced jet flight to American passengers six years later, and Boeing followed up with other successful jets, culminating in 1970 with the gargantuan Boeing 747, which still carries huge loads of passengers for thousands of miles. Supersonic passenger jets have also been introduced, though their poor cost-efficiency precludes their wide use at present. The Soviet-made Tupolev Tu-144 was the first in 1968, followed by Great Britain and France's collaborative Concorde in 1969.

Demands for military superiority continue to drive advances in aircraft technology. In 1993, the first B-2 "Stealth" bomber was delivered to the United States Air Force, the culmination of decades of development of the concept of the "flying wing." The Stealth's lack of right angles cause it to present a vanishingly small radar signal, rendering it very difficult to detect. The B-2's sister plane, the F-117 Stealth fighter, played an important role in the 1991 Gulf war against Iraq, and in 1997, the newest generation Stealth, the F-22 Raptor, took to the skies for the first time.

Similar demands in the realm of commerical aircraft have led to increasingly advanced and safe passenger jets. The two giant builders of commercial aircraft, the Boeing Aircraft Corporation and the European consortium Airbus Industrie, spurred by customer demands for reliability and cost-efficiency, now produce aircraft of remarkable durability and superior performance, as do numerous other commercial and general aviation aircraft manufacturers.

Less, than one century after the Wright brothers made their first tentative flight over Kill Devil Hill at Kitty Hawk, aircraft have evolved into the some of the most complex and succesful machines ever devised by the human mind. And although supersonic transports, radar-evading planes, and even space shuttles now seem almost commonplace, none of these advances in aviation would have been possible without the same kind of curiosity, imagination, and faith displayed by that English monk over nine hundred years ago.

This is the complete article, containing 2,730 words (approx. 9 pages at 300 words per page).