Spirit of St. Louis
Pan Am Clipper
All airplanes trace their origins back to the Wright Flyer. It was the first
plane to master the three essential elements of flight: lift, propulsion
and in-flight control. Orville and Wilbur
Wright knew, unlike many contemporaries, that control was the most important
factor for success. But the Wright Flyer would also embody the brothers'
genius in the areas of lift and propulsion. It was the combination of all
three elements that resulted in the extraordinary success of the Wright
Atop the wind swept dunes of North Carolina, it was with their gliders that the Wright Brothers first learned to master the control of pitch and yaw by horizontal and vertical rudders. For control of the plane's pitch, the Wrights used a front-mounted, horizontal biplane elevator attached to struts above the front of the landing skids. Manipulation of these two wings could control the up and down motion of the plane. For control of the plane's yaw, or turning motion, vertical rudders were positioned just behind the propellers. The control of lateral motion, or roll, was quite a different matter.
By observing the twisting action of birds' wings, the former bicycle-manufacturing brothers developed their own system of lateral control they called "wing-warping." The Wrights discovered that if the trailing edges of the wings were twisted in opposite directions, a differential in lift would occur, causing the plane to bank. Effecting this twisting was accomplished by a series of tethers and pulleys connecting the wings to a shoulder harness worn by the pilot. If a sudden gust of wind blew from the right, the pilot could instinctively roll his right shoulder down -keeping his balance like a bicycle rider would - causing the right wing to lose some of its lift. With less lift acting upon it, the right wing would settle down for level flight. In today's airplanes, this same function is carried out by ailerons.
Wing warping could work only if the plane had sufficient lift to achieve flight in the first place. After exhaustive wind tunnel research, the Wrights perfected their Flyer's airfoil shape. The wing's topside was curved slightly more than the bottom side. This caused air particles traveling across the top of the wing to be spaced out along the wing in a lower density than those traveling across the bottom of the wing. Therefore, higher pressure was exerted from below, causing the plane to rise, or lift, from the ground when propelled forward.
The Wrights' 12-horsepower, 4-cylinder engine powered an ingeniously designed set of propellers. While many contemporaries based their means of propulsion on the various screw-shapes used to propel ships, the Wrights built upon their knowledge of airfoils. They discovered that the airfoil shape could be used to create not only lift upward, but also propulsion forward. The shape of the Wright Flyer's propellers were therefore modeled after the shape of their wings. When the propellers rotated, they created a pushing instead of a lifting force.
With the groundbreaking design of the Wright Flyer, the Wrights' solutions to the problems of pitch, roll and yaw resulted in something never before achieved in countless attempts over thousands of years - the world's first sustained, controlled flight.
||The Wright Brothers
||December 17, 1903
||40 feet, 4 inches
||21 feet, 3/8 inch
||9 feet, 3.25 inches
||1 12-horsepower engine