Have you ever dreamed you could fl y like a super hero? What if you could actually soar through the air, glide over tree-topped hillsides, and dive through puff y clouds? T e idea of fl ying is nothing new. For


the past 2,000 years, people have been designing tools and machines to help them fl y. Some were wings, some kites, and others suits. Today, people use high-tech materials and know-how to design new ways to take to the skies. Some ideas copy birds and other fl ying animals. Other plans reuse old ideas. Some new ideas seem like they come right out of the future. Let’s explore some of the inventions that make the dream of fl ying a reality.


Gliding Through the Air First-time fl yers and experienced pilots oſt en use the word “peaceful” to describe hang gliding. Hang gliders have no engines, so fl ying in one is very quiet. Like birds’ wings, hang gliders take


advantage of a wing’s ability to create liſt . Liſt is a force. It opposes gravity. Gravity is the force that causes objects to fall toward the center of Earth. To be able to fl y, a machine’s liſt must be greater than gravity. A hang glider launches from the ground.


T e pilot straps on the 30-kilogram hang glider. It’s made from a light-weight, aluminum frame. It has a wing-shaped sail made of high-tech fabric. T e pilot sprints down the side of a steep


hill. Gravity pulls the glider forward as the pilot runs into the wind. T e sail catches the air and liſt s the pilot up.


12 NATIONAL GEOGRAPHIC EXPLORER


If the pilot runs fast enough, liſt


overcomes both gravity and drag. Drag is a force that slows things down. Running into wind can slow a pilot down. Once in the air, the pilot tucks his or


her legs into a fabric bag that hangs below the frame. Keeping the legs together in one place also helps reduce drag while in the air. Hang gliders have simple controls to


change their speed and direction. T e pilot does this by changing the angle of the wings. Experienced pilots can stay in the air for hours and travel great distances. When the pilot is ready to land, he or she adjusts the angle of the wings again. When the glider is near the ground, the pilot gets ready for a running stop.


A hang glider uses wind to create lift.


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