At the turn of the century, The Wright brothers’ ground-breaking inventions captured the spirit of innovation in our nation. Even today, their methods illustrate the importance of experimenting during the process of inventing.
Early Stages of Invention
On May 30, 1899, Wilbur sent a letter to the Smithsonian:
Dear Sirs: I am an enthusiast, but not a crank in the sense that I have some pet theories as to the proper construction of a flying machine. I wish to avail myself of all that is already known and then if possible add my mite to help on the future worker who will attain final success.
The Smithsonian sent the Wright brothers the material they requested. Indeed, at that time, the secretary of the Smithsonian, Samuel Langley, was deeply involved in his own aeronautical experiments. Langley was a brilliant, self-taught astronomer and physicist. He’d been experimenting with models and gliders since 1887.
In 1896, working in a shed located behind the Smithsonian Castle in Washington DC, he developed two unpiloted, heavier-than-air, steam-powered flying machines. They were launched from a catapult on a houseboat in the Potomac River and flew about three-quarters of a mile. Langley later received funds from the War Department to develop a piloted version.
The Physics of Flight
The Wrights studied Langley’s research and the reports of others, experimented with hang gliders, and posited that a successful airplane would feature three systems: one, a set of lifting surfaces, or wings; two, a method of balancing and controlling the aircraft; and three, a means of propulsion. They first concentrated on how to maintain balance and control, because they thought that was the toughest problem. Based on their experience, they realized that, like a bicycle, a flying machine would be fundamentally unstable as it traveled through air, yet, it could, like a bicycle, be controlled.
The Wright brothers realized that the wing on one side of a craft met the oncoming flow of air at a greater angle than the opposite wing, then it would generate more lift on that side, causing the wing to rise and the aircraft to bank. If pilots could manipulate the wings using this principle, they could maintain balance and turn the aircraft as well. The brothers considered but rejected using a system of gears and pivoting shafts to change the angles of the wings because it would be too heavy and too complex. Instead, they came up with the idea of twisting, or warping, the wing structure in controlled ways using interconnected wire cables.
Testing Gliders and Wing Design
In building their first experimental aircraft in 1899, a kite with a five-foot wingspan, the Wrights combined their wing-warping innovation with braced biplane wings inspired by the 1896 glider made by aviation pioneers Octave Chanute and Augustus Herring. That glider used steel wires crisscrossed between vertical wooden struts to support the upper and lower wings. Wilbur flew the test kite and the wing-warping controls worked well.
The brothers next turned their attention to testing the curve of the wing profile, the wing area necessary to lift a pilot, and the type of materials best suited to construct a glider. They needed wide-open spaces with strong, steady winds; they settled on Kitty Hawk, North Carolina. In 1900, they built a glider for about 15 dollars, which was cheaper than the cost of a bicycle at the time. They repeatedly tested it, flying it as a kite, and recording and analyzing the results. The glider was something of a disappointment, though, producing less lift than predicted. To increase the lift, they increased the wing size to a 22-foot span and changed its curvature, also known as the airfoil. They also changed the fabric covering the wing from a French cotton sateen to an unbleached cotton muslin. For the first time, the brothers could make real flights and these revealed very serious control problems.
They suspected that the information they used to compute lift and drag might be wrong, and so during the fall of 1901, they built their own primitive wind tunnel for testing the aerodynamics of different wing shapes. They increased lift efficiency with a thinner and longer wing and an improved airfoil for a new glider. Testing their third glider at Kitty Hawk in 1902, they decided on a movable rudder and integrated its controls with the wing-warping controls for better handling. The key here was a wooden hip harness, or a cradle, that enabled the pilot to move the wing-warping cables by jutting his hips this way or that. The brothers made somewhere between 700 and 1,000 glides; flights of 500 feet were common.
Wind-tunnel tests led them to further increase wing area to get the lift to carry the added weight of the engine, the two propellers, and all the structural reinforcement.
Now they could add a propulsion system. They designed a single 12-horsepower, gasoline-powered internal combustion engine to turn two propellers rotating in opposite directions behind the wings. Wind-tunnel tests led them to further increase wing area to get the lift to carry the added weight of the engine, the two propellers, and all the structural reinforcement. The wind-tunnel data were also crucial to the design of the very efficient propellers.
The Wright Brothers in Kitty Hawk
The Wright brothers then returned to Kitty Hawk in 1903 with what they simply called the Flyer. On December 14th, the Wrights were finally ready. They tossed a coin to see who would make the first attempt. Wilbur won. He climbed into the pilot’s position. The Flyer powered down 40 feet of rail; it was almost like a skateboard on a track, and it reached 20 miles an hour, and when it did, it lurched up, and it stalled, and it smashed into the sand, after a flight of three seconds.
But Wilbur Wright was confident. The plane was repaired, and it was readied for the next try on December 17th.
With Orville at the controls this time, the flyer darted up and sailed slowly over the sand and came to rest with a thud 12 seconds later, about 120 feet from where it had taken off. A man had flown.
See also: Planes, Trains, Automobiles … and Wagons.
…with Wilbur at the controls, the flyer flew 852 feet in 59 seconds, clearly demonstrating that the plane was capable of sustained controlled flight.
The Wright brothers made three more flights that day. Wilbur flew 175 feet; Orville then covered more than 200 feet in 15 seconds. And then, with Wilbur at the controls, the flyer flew 852 feet in 59 seconds, clearly demonstrating that the plane was capable of sustained controlled flight. Just after the fourth flight, a gust of wind overturned the airplane and sent it tumbling across the sand. Severely damaged, the 1903 Flyer never flew again.
Patents and the International Stage
Now, before revealing their triumph to the public, however, the brothers wanted to secure a patent and contracts for the sale of their invention.
The Wrights tested two more machines in an Ohio pasture in 1904 and 1905. By October 1905 they had transformed the experimental success of 1903 into the reality of a practical airplane capable of remaining aloft under the full control of the pilot for extended periods of time. Now, before revealing their triumph to the public, however, the brothers wanted to secure a patent and contracts for the sale of their invention. Their patent was for the system of controls, not the airplane. And finally, in the summer of 1908, Wilbur flew in public for the first time in France, while Orville flew for the U.S. Army at Fort Myer in Virginia….
The brothers wanted to find a permanent home to display their 1903 flyer. While disputes with the Smithsonian lingered for decades, Orville exhibited the restored Wright Flyer at the Massachusetts Institute of Technology and at aeronautical and automotive expositions in New York and in Dayton. In 1928, Orville shipped the Flyer to the London Science Museum…. The London Science Museum took very good care of the plane, and during the London Blitz in World War II, the Flyer was even evacuated with other important collections to a cave outside the city….
The Flyer came back to Washington after the war and after Orville Wright had passed away in 1948. It was exhibited in the Arts and Industries Building and then transferred to the National Air and Space Museum when it opened to the public in 1976.
It remains there today as one of the Smithsonian’s most popular and beloved displays.
From the Lecture Series Experiencing America: A Smithsonian Tour through American History.
Taught by Professor Richard Kurin, Ph.D.
Letter from the Wright Brothers to the Smithsonian, National Air and Space Museum, Smithsonian Institution; Wright Brother Flyer, National Air and Space Museum, Smithsonian Institution; Samuel P. Langley’s Aerodrome Shop in South Shed built in 1898 and located in the South Yard behind the Smithsonian Institution Building, National Air and Space Museum, Smithsonian Institution; Library of Congress, Prints and Photographs Division, LC-USZ62-65478; Library of Congress, Prints and Photographs Division, LC-DIG-ppprs-00556; Library of Congress, Prints and Photographs Division, LC-DIG-ppprs-00592; Library of Congress, Prints and Photographs Division, LC-USZ62-6166A; Wright Flyer in situ at the Air and Space Museum, National Air and Space Museum, Smithsonian Institution.