Definition: A series of developments that have allowed people to travel through the air in manufactured aircraft.
Significance: Since the earliest recorded history, people dreamed of flying, often ascribing the power to mythical gods. The airplane changed the world as has no other invention before or since by conquering the problem of distance.
Early Scientific Theories
Seventeenth century English physicist Sir Issac Newton postulated that heavier-than-air flight was impossible. Newtonian physics concluded that the resistance encountered by a wing would require an even heavier engine, which in turn would require an even larger wing, which would require an even heavier engine, and so on, in a circuitous conundrum.
The history of the science of human flight arguably began in 1680, when Italian physicist Giovanni Alfonso Borelli definitively proved that humans could not fly under their own power, because their pectoral muscles were simply too weak to support flight, regardless of the wing structures one might employ. That evidence should have ended tower jumping and flapping wing contraptions, but it did not. Some persisted, even into the twentieth century, in their preoccupation with the impossible. Others searched forless fatal alternatives, turning from flapping to floating.
Hot-Air and Hydrogen Balloons
An artist captured the supposed earliest recorded hot-air balloon demonstration, which was a small model, sent briefly aloft in 1709. Scientifically studying and documenting their efforts with pubic demonstrations, French brothers Joseph-Michel and Jacques-Etienne Montgolfier achieved the first true hot-air balloon ascents. On June 4, 1783, near Lyon, France, they demonstrated for the public their uncrewed aerostat, a huge linen bag lined with paper, 100 feet in circumference, which rose 6,000 feet aloft when a straw-fed fire heated the air inside the bag.
The Montgolfiers were not alone, however, in their quest for the sky. A series of scientific discoveries followed, and in 1766, hydrogen was discovered to be one-fourteenth the weight of air. French physicist Jacques-Alexander-Cesar Charles created his own version of the aerostat, crafting a rubber-coated silk balloon filled with hydrogen, which he publicly demonstrated on August 24, 1783, before a large crowd which included the American diplomat and inventor Benjamin Franklin.
During this period, the field of aviation experienced many pioneering firsts. In a demonstration before French king Louis XVI and his wife Marie-Antoinette at Versailles in September, 1783, the Montgolfiers sent aloft aviation’s first living voyagers: a rooster, a sheep, and a duck. The first crewed balloon flight came on October 15,1783, with volunteer Jean-Francois Pilatre de Rozier, a young doctor, on board. The original plan had been to send aloft two criminals from prison, in case they did not come down alive. However, Pilatre de Rozier insisted on taking the place of the prisoners. OnNovember21,1783,he and the marquis Francois d’Arlandes flew untethered across Paris. On December 1, 1783, the first crewed hydrogen balloon ascended with Charles and a passenger. After a lengthy two-hour, 27-mile flight, Charles set down, left off his passenger, and made a second flight, at sunset. With one less person aboard, the balloon rose to 9,000 feet, and Charles became the first person to see the sun set twice in one day.
With these first successes also came tragedy. The first to fly was also the first to die. Pilatre de Rozier, in attempting to cross the English Channel on June 15, 1785, combined the hot-air-and-hydrogen balloon technology, putting a fire under a hydrogen balloon. The flight lasted only four minutes before exploding and killing its pilot.
Military use for the balloon was not far behind, starting a familiar sequence which would be repeated throughout history. In June, 1793, the French Republican government put observers in tethered balloons to report on enemy movements. In April, 1794, the French formed the first balloon corps, used in several European campaigns but disbanded by Napoleon in 1802.
Powered Flight
The matter of balloon steering remained unresolved until the twentieth century, when the elongated steerable dirigible was developed. At about the same time, the first powered airplane was invented. These near-simultaneous achievements were not serendipitous. Both enterprises depended on the same thing to succeed: a suitable engine to power the aircraft.
Although early engines were problematic, they held greatpromise. In 1876, German engineer Nikolaus August Otto designed and built the world’s first practical internal combustion engine to use liquid petrol as fuel. In 1885, simultaneously and independently, German engineers Gottleib Daimler and Carl Benz built the first lightweight, high-speed petrol engines.
Gliders and Winged Flight
Although Orville and Wilbur Wright’s secret to success in achieving the first powered flight was the engine they designed and built themselves, the two brothers researched, designed, tested, and built the plane, propellers, and control surfaces and structures that ultimately helped them to succeed. They systematically and scientifically studied the work of early glider pioneers, most notably that of the British Sir George Cayley, known as the father of aeronautics.
In 1804, Cayley had built the first known heavier-than-air flying model. Over the next fifty years, he built three full-scale gliders capable of flight with a passenger on board. In 1871, the wind tunnel was invented to enable the aerodynamic study of scale models. The Wrights perfected their own wind tunnel and used it systematically to study and perfect their wing and propeller designs. Their scientific approach enabled them to succeed where others had failed.
Another glider great, the German aviation pioneer Otto Lilienthal, developed and flew controllable gliders, working from 1891 until his death in 1896 while attempting a powered glide. He tested his gliders by leaping from an enormous hill he had built near Berlin. The Wrights, too, began by experimenting with gliders.
Still others would play a role in the Wright’s story by disseminating information. Octave Chanute was a French-American engineer credited with building the first bridge across the Missouri River and the stockyards in Chicago and Kansas City. Bored with engineering for trains and livestock, he turned his attention to aeronautics. In 1894 he published Progress in Flying Machines, which collected and summarized the information humans had learned to date about heavier-than-air flying machines. On May 13, 1900, Wilbur Wright wrote to Chanute to introduce himself and inquire about available information that would assist the Wrights’ experimentation.
The Wrights had learned of Chanute after having written the Smithsonian Institution seeking information on flying. They learned that Samuel Pierpont Langley, the director of the Smithsonian, was experimenting with heavier-than-air flight. Langley had received the first federal government contracts to build a powered human-carrying plane, but both his attempts, with planes launched from atop a houseboat in the Potomac River, were failures. He gave up in disappointment, most of his calculations proven embarrassingly incorrect when, one week later, he was beaten by the Wrights in the race to fly.
The Wright Brothers’ Achievement
It is almost impossible to overstate the significance of the Wrights’ accomplishment. Through careful study and diligent testing, they unlocked the secret to controlled flight. By wing warping, or twisting, they could cause the plane to turn. This mechanism was the forerunner of the aileron on modern planes. The Wrights systematically studied aspect ratios, comparing the wing’s length to its width, and devising tables to decide on the most suitable wing sizes and shapes. They researched propellers in their wind tunnels, understanding that the propeller was a rotary wing with forward lift. They defeated torque by using two propellers rotating in opposite directions, connected to sprockets by a bicycle chain. When they could find no satisfactory engine, they designed and built their own.
At their testing grounds at Kitty Hawk, North Carolina, on December 17,1903, at 10:35 a.m., the Wright brothers made their first flight, with Orville at the controls, and Wilbur running alongside him. Orville had positioned a camera before the flight, and John T. Daniels, a volunteer helper who had run up from the Kill Devil Hill Life Saving Station, snapped the picture of the first powered, sustained flight by humankind. The Wrights made four flights that day. The longest, with Wilbur at the controls, lasted 59 seconds and covered 852 feet.
In many ways the most important part of the history of flight was over on the day it began. The scant one hundred years in the history of human flight show astonishing discovery and achievement, but in reality, much remains exactly as it was researched and recorded in the Wrights’ early records. In the next two years, the Wrights built more airplanes and made more discoveries about piloting them: how to control, turn, and avoid stalls. In January, 1906, the Wrights offered to sell their plane to the U.S. War Department, which declined. In 1907, they took their plane to Europe, seeking in vain to find a buyer overseas. The Wrights left their airplane stored in a shed in Europe and returned, dejected, to Dayton.
In 1908, however, the British Army acquired the Wrights’ aeroplane number 1 and the U.S. Army agreed to pay the Wrights $25,000 for one of their airplanes. A French group agreed to pay $100,000. Wilbur went to France, got the plane out of the shed and upgraded it with some recent advancements.
To fulfill the U.S. government contract, Orville went to Fort Myer to test-fly the airplanes. Tragedy struck on the last day of the test flights, and a twenty-six-year-old lieutenant, Thomas Selfridge, became the first person to lose his life in an airplane accident.
Thereafter, the aviation firsts came in rapid succession. In 1909, French aviator Louis Bleriot flew across the English Channel in a self-built monoplane. The public’s fascination with aviation was fueled by air meets that occurred on both sides of the Atlantic Ocean. By 1910, there were nighttime takeoffs, makeshift lighted beacons and runways, stunt flying, and the first takeoff from a ship deck. The next few years brought ship-deck landings, the first U.S. transcontinental flights, the crossing of the Mediterranean and the establishment of the British Royal Flying Corps. With heavy initial losses and little early success, the U.S. Signal Corps was also established.
Airplanes as Warplanes
OnJune28,1914,Europe was thrown into World WarI. At the start of the war, there were 1,200 German planes, and 1,000 French and British planes. On April 6, 1917, the United States entered World War I, and a U.S. military aviation section was established. Although 1,000 men enlisted, fewer than 250 planes were amassed.
Fighter planes and their pilots would earn fame and affection during World War I. Eddie Rickenbacker of Columbus, Ohio, who later helped found Eastern Air Lines, was the top U.S. ace, and also flew for France with the U.S. volunteer group, the Lafayette Escadrille. General William “Billy” Mitchell, returned home in 1919 from his European service advocating an independent U.S. air power. He predicted the attack on Pearl Harbor decades before its occurrence and forced the U.S. government to examine what had happened to money appropriated by Congress for World War I fighter planes that were never delivered. Justice Department investigations and Congressional hearings were held, but eventually Congress tired of the issue and agreed not to pursue the matter further.
Aviation in the Interwar Years
After the war was over, airplane travel offered a way around the war’s destruction and devastation, and, in combination with ground transportation, allowed access to far-flung colonial outposts. European governments directly subsidized the development of commercial air carriers, such as KLM, Lufthansa, British Airways, and Air France.
The U.S. government, in contrast, opposed direct subsidies for the development of commercial air carriers, but instead used U.S. airmail contracts to establish and subsidize the aviation industry. In 1925, air mail was privatized, and wealthy American industrialists snapped up the first contracts. As aircraft improvements were made and more reliable engines were developed, navigational aids helped to make flying a more certain venture. In 1926, government regulation and certification of pilots, aircraft, air traffic rules, maps, weather reports, and accident investigation aided the private air carriers by improving the safety, efficiency, economics, and reputation of flying.
American fliers and planes soon established their worldwide dominance in the field of aviation. The first around-the-world flight was accomplished by Douglas Aircraft World Cruisers, manufactured in Santa Monica, California. Four Cruisers departed Seattle, Washington, on April 6, 1924, and two Cruisers returned to the same spot 27,553 miles and 175 days later, on September 28. Seven years later, a similar feat was accomplished in just eight days, when American aviator Wiley Post circumnavigated the globe.
In May, 1927, Charles A. Lindbergh, flying from New York to Paris, became the first pilot to make a solo transatlantic crossing. He was immediately lauded as a hero and remains among the most famous fliers in history. Lindbergh would go on to devote his life to the promotion of both civil and military aviation. In 1932, Amelia Earhart crossed the Atlantic solo, and fame followed her flight. She was lost in 1937, attempting to circumnavigate the globe via the 27,000-mile equator route.
The record-setting flights of the 1920′s and 1930′s bear witness to the fact that during this period, planes were undergoing dramatic technical improvements. No airplane before or since has captivated the world, or its aircraft sales, as did the Douglas DC-3. Still the most successful transport plane ever, with 10,926 manufactured in the United States, and perhaps as many as 5,000 more manufactured overseas by other countries, the twin-engine DC-3, also known as the Gooney Bird, Dakota, or Skytrain, along with the DC-4, also known as the Skymaster, with double the DC-3′s engines, passenger capacity, and range, revolutionized air transportation.
Alternate Methods of Flight
Other methods of human flight rose, or fell, in the 1920′s and 1930′s. In 1926, American physicist Robert H. God-dard demonstrated the liquid fuel rocket. In 1936, the first truly successful helicopter, the Focke-Wulf, was developed in Germany. In 1937, British engineer Sir Frank Whittle established the world’s first turbojet engine development program. Zeppelin airships, two and one-half times the length of a football field, were first launched in 1909 and began commercial service in 1911. Zeppelins provided the world’s first passenger airline service. On May 6, 1937, the world’s largest airship, the hydrogen-filled Hindenberg, exploded while approaching moorings in New Jersey, after completing a trip from Germany. Although lives had been lost in zeppelin travel until the Hindenberg disaster, the loss of the airship, captured on film and rebroadcast worldwide, ended the era of the airship, a scant thirty years into its history. Today, the sight of a helium-filled blimp overhead is a rare occurrence usually confined to the airspace over sporting events.
World War II
As the 1930′s drew to a close, war again loomed in Europe and Asia. In 1932, Japan employed aircraft carriers in conflicts with China. In 1935, Italy used air forces to invade Ethiopia. In 1936, the nation sent air forces to aid General Francisco Franco in the Spanish Civil War, as did Germany, which had sent troops to Italy for secret pilot training. By 1938, Germany had reached wartime levels of airplane production. The Soviet Union sent planes to Spain to help defend against Franco’s forces. In 1939, the Soviet Union aided China against Japan, as did the United States, with its American Volunteer Group, also known as the Flying Tigers.
On September 1, 1939, German chancellor Adolf Hitler invaded Poland. The Luftwaffe, the German air force, struck the Polish airfields, taking out most of Poland’s planes. In 1940, Denmark, the Netherlands, Belgium, and France fell to the Germans. Beginning on September 7, 1940, Hitler’s Luftwaffe commenced nightly bombing of London. Aided in part by radar warning stations, London and Britain held, and Hitler turned his attention elsewhere when he failed to achieve control of the air in the Battle of Britain. In 1941, Hitler invaded the Soviet Union. Although the Soviets suffered significant casualties and the loss of 8,000 planes, the German planes could not reach the Soviet aircraft factories, and the Soviets kept building.
In the United States, airplane production had been dramatically increasing throughout the late 1930′s. In 1938, airplane production was increased to 10,000 units per year.
On December 7,1941, the Japanese attacked Pearl Harbor, Hawaii, much as Billy Mitchell had predicted. In rapid succession, the Philippines, Hong Kong, Singapore, Malaya, the Dutch East Indies, Borneo, and Burma fell to the Japanese. In 1942, American bomber groups were deployed over Tokyo, Europe, and Africa. In 1943, the Eighth Air Force began attacks on Germany, and the Fifteenth Air Force began attacks on Italy. By 1944, U.S. aircraft manufacturers had produced 96,318 planes in one year. On May 7,1945, Germany surrendered, even though it had developed formidable new weapons in the V-1 pilotless bomber jet and the V-2 missile, with a 2,000-pound warhead, a range of220 miles, and a speed of up to 3,600 miles per hour.
Meanwhile, the air war raged on in the Pacific. The United States continued its strategic bombing of Japan withB-29 aircraft. The threat posed by Japanese kamikaze suicide bombers increased, as it surfaced that Japan intended to use the majority of its remaining planes as kamikazes. The decision was made to use the atomic bomb on Japan. On August 6, 1945, the first bomb was dropped on the city of Hiroshima, and a second was dropped on Nagasaki on August 9. Within six days, Japan had surrendered.
Berlin Airlift
After World War II, Germany was literally divided in two. East Germany was walled off by the Soviet Union and placed under a Communist government. West Germany was free and protected by U.S. forces. Landlocked within East Germany was the city of Berlin, half of which was not under Communist control and was protected by the U.S. and its allies. In 1948 and 1949, the United States airlifted food and supplies into Berlin, using Douglas C-47 and C-54 aircraft, in what was at the time the largest humanitarian effort in history.
An Independent U.S. Air Force
Following World War II, the United States altered its development and use of military aircraft. In 1947, the Army Air Corps became the newest branch of the armed forces, and the U.S. Air Force and the Central Intelligence Agency (CIA) were created. These two acts were not independent. The CIA, the Air Force, and private aerospace contractors worked together to develop new aircraft and intelligence technologies. One such facility, Lockheed Corporation’s secret development division was dubbed the “Skunk Works,” and its projects were so classified that they did not appear even in federal budgets. In 1947, a military plane broke the sound barrier.
The Cold War
Although World War II had ended, the Cold War took its place. A handful of the world’s most powerful nations possessed the capability to make and deploy nuclear weapons. The United States and the Soviet Union, former World War II allies, both developed intercontinental ballistic missiles (ICBMs) capable of attacking the other nation when launched from home soil. The deterrent effect of these weapons was called mutual assured destruction (MAD). The destructive capabilities and the distrust between the two superpowers spurred the space race, as well as military actions in other parts of the world.
The Korean War
On June 25, 1950, Communist North Korea crossed the thirty-eighth parallel, invading free South Korea. The Soviet Union aided North Korea, and the United States helped to defend South Korea. November, 1950, saw the world’s first all-jet air battle between a Soviet MiG and a U.S. F-80 Shooting Star. Later, the U.S. F-86 Sabre jet would prove an even tougher opponent against the MiGs. On July 27,1953, an uneasy armistice was signed, but difficulties persisted, and U.S. forces continued to help defend the peace.
The Jet Age
In the 1950′s civil aviation also entered the jet age. In May, 1952, the British De Havilland Comet commenced passenger service. Soon after entering service, three such planes seemingly came apart in midflight. By April, 1954, the plane was grounded, and the American Douglas DC-8 and the Boeing 707 came to dominate the world’s jet passenger airline market, giving their manufacturers the lead in the industry for years, until a European consortium was formed in 1970 to manufacture the Airbus aircraft.
The Space Age
The Soviet Union led the early space race, with a series of firsts. In 1957, the Soviet Union sent Sputnik, the world’s first Earth-orbiting satellite, into space. In 1961, the Soviet cosmonaut Yuri Gagarin became the first human in space with his Earth-orbiting mission Vostok 1. The United States followed shortly thereafter with Alan Shepard, Virgil “Gus” Grissom, and John Glenn.
In the early 1960′s international attention and tensions were also riveted by the work of American spy planes when the Soviets shot down an American U-2 plane and captured its pilot, Gary Powers, and spy plane photographs revealed Soviet movement to put missiles on Cuba, within range of the United States.
The Vietnam War
Events in Southeast Asia during the 1950′s and 1960′s involved the United States in another war and again tested the nation’s air power. While trying to stabilize a tenuous political situation between North and South Vietnam, the United States was drawn into a police action that would occupy two presidents and divide the American people. The Vietnam War was called the first television war, with fighting broadcast on the nightly news.
Memorable Events in Flight
Many people claim there are events in history that are so important that every person who was alive and sentient can remember exactly where they were and what they were doing when it happened. One such event was the assassination of President John F. Kennedy onNovember22,1963. Another three involve human flight. On July 20, 1969, the Eagle lunar landing craft set down on the surface of Moon, where U.S. astronauts Neil Armstrong and Edwin “Buzz” Aldrin left footprints and an American flag. Another such event is the January 28,1986, explosion of the space shuttle Challenger, which killed seven astronauts, including Christa McAuliffe, the first teacher in space. The third day is September 11, 2001, when four hijackings resulted in the deaths of almost five thousand people at the World Trade Center and the Pentagon.
Operation Desert Storm
By 1991, when Americans would watch another war on television, aviation had evolved significantly from the time of the Vietnam War. During the Gulf War, missile-mounted cameras delivered photographic images while delivering bombs with exactitude measurable in inches, without risking American fliers. Global Positioning System (GPS) satellites had been placed in orbit and delivered with inexpensive handheld units target exactitude. One-half million American military personnel and the armament and equipment to support them were delivered to the other side of the world. The war was over within days. For the first time since the invention of the airplane, there was a war with no aces.
Highway in the Sky
The technology revealed in Operation Desert Storm helped to revolutionize the world of civilian aviation throughout the late twentieth century. The U.S. air traffic control (ATC) system had been pinning its hopes on a new microwave landing system, which was scrapped in favor of the astonishingly accurate GPS system. Computer flight control and navigation technology was adapted for affordable installation in small general aviation and personal aircraft, delivering military precision and failsafe computer systems for private pilots.
The ability to wage war without legions of pilots convinced the U.S. Joint Chiefs of Staff that the military should develop uninhabited aerial vehicles (UAVs) for both intelligence and weapons delivery. Lightweight and quiet jet engines and lightweight but strong composite flight structures were developed for the job. The military was not alone in realizing the value to human flight of such engines and materials.
In 1977, one of the oldest obstacles to human flight was finally overcome, when Gossamer Condor, powered by pedals, made the first human-powered flight. Its designer had worked with extremely lightweight but strong materials, as had Jeana Yeager and Dick Rutan in piloting the Voyager, which in 1986 became the first plane to make a nonstop transglobal flight without refueling. The 1903 Wright Flyer and the 1988 Voyager sit side by side at the National Air and Space Museum, awaiting the next addition in the history of human flight.
