At the beginning of the 20th century, travel from Europe to America took 7 to 10 days by boat. By the end of the century, the same trip took 4 hours on the Concorde. The speed and efficiency of air travel have made personal and cultural exchange possible on a global scale. And the extraordinary engineering developments that shaped the airplane's evolution weave one of the most dramatic stories of the 20th century.
In 1903, the first powered, sustained, and human-piloted flight carried Wilbur Wright 120 feet in 12 seconds. Later that day Orville Wright flew 852 feet for 59 seconds. Today, people worldwide commonly fly thousands of miles each year for business and pleasure.
Perhaps the most amazing achievements in aviation were at the beginning of the century, when little was known about flight. This was a time of intuitive creation and experimentation - with wing size and shape, with materials, and with power systems.
Early flight was a risky and daring undertaking. Fliers were called "aeronauts," a title that reflected the dangers they faced. Planes were noisy and low-flying craft made of cloth or wood. The cockpit was completely open, leaving the pilot unprotected from weather and other hazards. Fuel was still unrefined and therefore not always reliable, and crash landings were not uncommon. There were no guidance systems or satellites to warn of storms or other weather hazards. The first "road maps" for pilots were directional signals painted on barn roofs. Flying at night was not a good idea, although in the 1920s a series of rotating beacons were set up every 50 miles or so across the country to guide planes — a far cry from the sophisticated air traffic control systems of today.
The Wright brothers' success was built on the pioneering work of German engineer Otto Lilienthal with gliders, and Octave Chanute, an American who worked on multiplane gliders. The race to be the first to fly successfully was a worldwide competition, and pioneers like Samuel Pierpont Langley and Gustave Whitehead were serious contenders. Though the Wright brothers' historic flight in 1903 is now recognized as the true beginning of aviation, the feat was largely ignored at the time. It wasn't until 1908, when Orville successfully flew for an hour, that the world began to take flight seriously. From then on, excitement for this new enterprise inspired a flurry of refinements in Europe and the United States. A myriad of odd-looking crafts of every configuration began to appear, powered by everything from catapults to steam and gas engines.
The Wright brothers did not want to compete in this field - they wanted to dominate it, and so fought many patent wars with early experimenters, most especially with Glenn Curtiss, who claimed that he had completed the first successful flight in 1901. These patent conflicts limited the development of aviation technology in the United States, until a different kind of conflict - World War I - finally put an end to them. The U.S. government declared it a patriotic necessity for cross-licensing agreements between the Wright and Curtiss companies, and this opened the door for many other innovators.
Only 11 years after Kitty Hawk, the war ignited a race to bring combat to the skies, with the hope of early victory. This gave great impetus to technological development and transformed small-scale aircraft manufacture into a unified national concern. Numerous innovations in materials and design were needed quickly just for planes to survive the rigors of combat. Flammable plywood and fabric were soon replaced with metals like iron and welded steel tubing (as in German Junkers), and wings were streamlined (as in the German Albatross). Anthony Fokker refined the design of maneuverable triplanes and developed the interrupter gear that synchronized machine gun fire with the spinning propeller, thus giving Germans air superiority in 1916.
The Allies countered with more powerful engines and shifted manufacturing techniques in other industries to the production of aircraft. During this period, thousands of aircraft were produced by both sides. Many were untested planes, quickly and prematurely pressed into service, which often broke apart in the air. Given the short history of aviation, most pilots were grossly inexperienced. Both factors left a legacy of fatal mishaps, and a resolve to explore more sophisticated aviation techniques.
The war proved that airplanes could be easily adapted for civilian uses, transporting mail, passengers, and cargo. The DC-3 made its first appearance in 1935 and represented a major leap forward in airplane development, proving airline travel economically practical. It incorporated the technical advances of the day, including metal skin; an internally instead of externally braced design; an almost completely enclosed engine that reduced drag; the addition of wing flaps, and variable-pitch propellers. By 1941, the DC-3 provided 80 percent of scheduled domestic service.
In 1939 the gas turbine was introduced, signaling the beginning of jet transport. Working independently, Sir Frank Whittle in England and Hans von Ohain in Germany both developed this technology, though von Ohain's was the first to successfully power an aircraft. French engineer Rene Lorin visualized the concept of jet propulsion more than 25 years earlier, but it took improved materials and the genius of Whittle and von Ohain to recognize the advantages that a gas turbine offered over a piston engine, including speeds in excess of 350 miles per hour.
World War II saw another period of rapid innovation, as the race to early victory forced advances in engines, fuel, materials, and testing, giving way to more powerful engines, new methods of construction, and navigational and bombing systems. After the war, a return to building passenger and cargo planes continued on a worldwide scale. By 1957, airplanes would surpass trains as the preferred mode of travel for Americans. "Bigger, better, faster" was the slogan that drove production. Today's modern jetliners can carry hundreds of passengers, and the Concorde offers supersonic transport between the United States and Europe in four hours.
In addition to commercial aviation, general aviation has also become a burgeoning field for business and pleasure, and today it accounts for some 600,000 pilots in the United States. General aviation makes thousands of small airports and landing strips accessible to air travel, freight, and ambulance service. Pioneers in the field include Clyde Cessna, Walter Beach, and William Piper. Thousands of people build and fly their own planes, and are the real innovators in aviation today. Outstanding among them are Burt Rutan, who designed the first plane to circle the globe nonstop, and Paul McCready, who designed human-powered planes (the Gossamer Albatross and Gossamer Condor). Both have made important contributions to the aviation industry in terms of materials, fuels, and design.
The development of rotary-wing aircraft came into its own in the postwar era. More powerful engines and improved transmissions helped spur a frenzy of experimentation. One aircraft, the Bell XV-15, combined elements of the helicopter and fixed-wing craft. After vertical takeoff, the plane could tilt its rotors forward and fly like an airplane. Since Leonardo da Vinci's designs for an "airscrew," humans have been intrigued by ways to achieve vertical flight. The Wright brothers recognized that a propeller was actually a rotating wing. They and others applied the principle to autogyros, which achieved short flights, but, because they had no power systems, couldn't climb, descend, or fly sideways or backwards. The first public demonstration of a fully controllable rotary-wing aircraft, the helicopter, was Germany's Focke-Achgelis Fa-61 in 1936. In the United States, Igor Sikorsky made his first successful flight with the VS-300 in the summer of 1939, launching a dynasty that dominated the helicopter industry for most of the century.
Airports - once grassy fields with wooden shacks for terminals - are now major architectural statements. Beyond providing a safe surface for takeoff and landing, airports now host shops, restaurants, and service establishments. Air traffic control systems keeps the world's pilots connected, guiding them safely to and from their destinations. In the United States, airports employ more than a half million people, and related services and aviation activities account for more than 6 percent of the nation's gross domestic product.
Perhaps the greatest outcome of this technology has been the expansion of our personal horizons. As we contemplate what the next century of flight will bring, Orville Wright's early prediction seems appropriate. He said, "I cannot answer except to assure you it will be spectacular."
