When the airspeed reached about 17 mph (27 kph), I could feel the hang glider lift me off the ground. To take off, I lifted the hang glider (about 65 pounds / 29 kilograms) by the sides of the control bar and ran down the ridge (the instructor ran along side and shouted directions). Next, because Jockey's Ridge is a public park, he checked to make sure that our intended flight path was clear of obstacles and people. Before the flight, the instructor conducted a pre-flight inspection of the glider, checking to make sure that all of the hardware was in good condition, including the sail, battens, cables, tubes, bolts and harness connections. The goal of our lesson was to take off, fly in a straight line down the ridge and land upright. Several years ago, I took a basic hang-gliding lesson from Kitty Hawk Kites at Jockey's Ridge, NC, which is a large sand dune (80 to 100 ft / 24 to 30 m high). Photo courtesy Sky Masters School of Hang Gliding Variometers and altimeters are especially important for high-altitude or long-distance (cross-country) flights. In addition to visual displays, variometers have audio displays so the pilot doesn't have to look at the dial to know his climb or descent rate.
Some pilots carry instruments such as an altimeter, to keep track of the glider's altitude, and a variometer that keeps track of glider's climb or descent rate. Other safety equipment includes goggles for eye protection and glare reduction (similar to ski goggles) and a reserve parachute, usually for high-altitude flights (several-thousand feet up).
The most basic piece of safety equipment is the helmet, which protect the pilot's head. Some are insulated especially for high-altitude flights.
Harnesses come in many styles and hold the pilot in a prone position. It suspends the pilot from the glider in such a way as to allow him or her to move freely. The harness attaches to the center-of-mass of the glider, just behind the control bar. In stalling, no air flows over the wing so the glider can't fly. If the pilot pushes forward on the glider, tipping its nose up, the glider slows down or even stalls. If the pilot pulls back on the glider, tipping its nose down, the glider speeds up. The pilot can also change the angle that the wing makes with the horizontal axis ( angle of attack), which determines the airspeed and the glide ratio of the hang glider. Instead, the pilot is suspended from the hang glider's center-of-mass (hence the term "hang" glider) by way of a harness, maneuvering the hang glider by shifting his or her weight (changing the center-of-mass) in the direction of the intended turn. Unlike soarplane gliders, hang gliders have neither movable surfaces on the wing nor a tail to deflect airflow and maneuver the craft. The performance of a hang glider and the distance it can travel is determined by its glide ratio ( lift/drag ratio), the ratio of the forward distance traveled to the vertical distance dropped. The amount of drag is proportional to the airspeed of the hang glider: The faster the glider moves, the more drag it creates (see How Gliders Work for details).Īs with soarplane gliders, the balance of these three forces (lift, drag, gravity) determines how high the hang glider can go, how far it can travel and how long it can stay aloft. The frictional force caused by these collisions is known as drag, which slows the glider down. As the hang glider and pilot move through the air, they collide with air molecules.
In addition to the horizontal movement of air, hang gliders can get lift from rising currents of air, such as columns of hot air ( thermal lift) or air deflected upward by mountainous or ridge topography ( ridge lift). Once aloft, gravity (the weight of the hang glider and pilot) pulls the glider back toward Earth and propels the glider forward, continually causing air to flow over the wing. This movement of air over the surface of the wing generates lift, the force that counters gravity and keeps the glider aloft. To launch, the pilot must run down a slope to get air moving across the wing at about 15 to 25 miles per hour (24 to 40 kph).
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