It Flies!

By Kristina Dell

In June 1899 a letter arrived at the Smithsonian Institution in Washington. "I am an enthusiast but not a crank," wrote a bicycle-shop owner from Dayton, Ohio. "I wish to avail myself of all that is already known and then if possible add my mite to help." The letter was from Wilbur Wright, who, with his brother Orville, wanted to build an airplane. They began with kites and gliders, built their own wind tunnel and even recalculated long-accepted physics equations. Four years later on a blustery North Carolina beach, they succeeded where all others had failed. The longest flight was only a minute, but a new era had begun.

1 LIFT

WINGS Other inventors had discovered that curved wings reduce air pressure above and increase it below, resulting in an upward push, or lift. While most used a perfect-arc design, the Wrights put the high point of the arc nearer the leading edge. They believed this would increase the Flyer's stability by keeping the wings balanced over the center of pressure, where lift is focused, as the plane moved up and down during flight

2 PROPULSION

PROPELLERS Unlike their predecessors who copied boat propellers, the Wrights realized that a propeller works like a rotating wing. The same forces that create lift could generate thrust. The Wright Flyer had two propellers, which moved in opposite directions

ENGINE The Wrights couldn't find an engine that met their needs, so they had one built from lightweight aluminum. Propellers were connected to the engine by a chain-and-sprocket transmission that resembled a bicycle's

3 CONTROL

STEERING The brothers' most important achievement was their three-dimensional control system: it's why their Flyer worked when other planes didn't. The Wrights realized a plane could not be turned with just a rudder, like a boat; it had to bank into turns to stay under control

For directional control, the Wrights created wing warping--twisting the wings to facilitate turning. The pilot's torso rests in a wooden hip cradle that is connected by wires to both wings' rear corners and to the rear rudder

By shifting his hips to one side, the pilot pulls the opposite wing tip down, while the other automatically twists up. The side with the trailing edge down experiences more lift

The increased lift causes the Flyer to bank into a turn. The rudder keeps the turn under control

ELEVATION AND DESCENT For vertical control, a wooden hand lever was connected by a chain and pulley to an elevator in the front. By pulling the hand lever back, the pilot rotated the elevator, causing the plane to rise. Pushing the hand lever forward would cause the plane to descend

FIRST FLIGHTS On Dec. 17, 1903, the Wrights made four flights, each progressively farther:

Flight 1 120 ft. (37 m), 12 sec., Orville flying

Flight 2 175 ft. (53 m), 12 sec., Wilbur flying

Flight 3 200 ft. (61 m), 15 sec., Orville flying

Flight 4 852 ft. (260 m), 59 sec., Wilbur flying

MILESTONES OF AVIATION In less than a century after Kitty Hawk, pilots were flying across the oceans, around the world and into space

1900s

Dec. 17, 1903 Wright brothers' flights at Kitty Hawk, N.C.

1910s

Jan. 15, 1914 First scheduled airline service flies across Tampa Bay, Fla.

1920s

May 2-3, 1923 First nonstop flight across North America takes 26 hr., 50 min.

May 21, 1927 Charles Lindbergh completes solo flight across the Atlantic

1940s

Oct. 14, 1947 Chuck Yeager breaks the sound barrier

1960s

July 20, 1969 Apollo 11 lands two men on the moon

1970s

Jan. 21, 1976 British Airways and Air France begin supersonic passenger flights

1980s

April 12-14, 1981 First space shuttle launched into orbit and returns to Earth

2000s

By 2005 Airbus is building the A380; it could seat more than 800

Sources: National Air and Space Museum, Smithsonian Institution; National Park Service; NASA; How We Invented the Airplane, by Orville Wright, 1988 edition (Dover); First Flight, by T.A. Heppenheimer, 2003 (Wiley); On Great White Wings, by Fred E.C. Culick and Spencer Dunmore, 2001 (Hyperion)