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Flights of Discovery
Humans have always been fascinated by flight. Kites gave people a chance to experience flight secondhand, and the invention of hot air balloons and gliders provided them with a true bird’s-eye view. But it wasn’t until Orville and Wilbur Wright made the first powered, controlled flight in 1903 that air travel really took off.
Now we think nothing of traveling from coast to coast in a matter of hours. It’s easy to forget that air travel was made possible by the efforts of scientists, mathematicians, and inventors over hundreds of years. They all studied the work of those who came before them. Then they posed a question and set about solving it: Why do objects fall to the ground? Do heavy objects fall faster than light objects? What keeps birds aloft? How can we fly farther and faster? Is it possible to break free of Earth’s atmosphere?
Today we’re still asking and answering questions about flight. Who knows—someday you may discover a better way to fly. You can start by learning about the basic physical forces behind the science of flight.
Paintings dating back thousands of years show that people have always been fascinated by flight.
In 1903 Orville and Wilbur Wright completed the first powered, controlled flight in the Wright Flyer. The Flyer used two rear propellers to generate thrustt. It had airfoil-shaped wings to create lift.
Everything that flies—a bird, a glider, a helicopter, or a jet airplane—is pushed and pulled by four forces: gravity, lift, drag, and thrust. An airplane must harness these forces to fly effectively.
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LIFT The airplane’s wings produce an upward force called lift that counteracts gravity. |
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| DRAG A force called drag, caused by air resistance, slows the airplane down. |
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THRUST To fight drag, the airplane uses a propeller or jet engine to produce a forward force called thrust. |
| GRAVITY The force of gravity pulls the airplane downward. |
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Download a printable, letter-size version of the classroom poster on the introduction to Forces of Flight. Adobe Acrobat® version (file size: 214 KB) Download Now |
