FUNDAMENTALS OF HANG GLIDER FLIGHT

Safety equipment is a major issue with pilots. All pilots, on the training hill or flying the mountains, wear a helmet during every flight. For flights over 200 feet, pilots carry parachutes. Parachutes designed for today's hang gliders are attached both to the pilot's harness and the hang glider itself. In the event of an accident requiring its use, the pilot deploys the chute, allowing both glider and pilot to come down gently beneath the canopy.

Unlike conventional aircraft, the hang glider pilot's body forms part of the aerodynamic unit and is used to control the glider's flight. Gradually, body and glider blend into a single machine, and the pilot loses conscious awareness of their separateness. By the time the pilot has learned to fly his hang glider with birdlike freedom, he not only knows intellectually all about his craft and the air in which he maneuvers, he has also acquired some of the sensory awareness of the creatures he imitates. His skill becomes instinctive behavior.

The actual control movementds of the hang glider are accomplished simply by moving one's weight through the use of the control bar: pulling your weight forward causes the nose of the glider to come down and the hang glider to accelerate or dive. Pushing your weight back from the control bar makes the nose of the glider come up, which causes the hang glider to slow down. By pulling your weight laterally to the right, the wing tilts to the right, and by pulling your weight to the left the wing tilts left, causing either a right or left turn, respectively. A skilled hang glider pilot executive a series of extremely complicated maneuvers whole control is based on these four simple actions. Gaining the knowledge that turns these four elemental control movements into a safe and exhilarating flight is the challenge of all new hang glider pilots.

Like other aircraft, a hang glider is dependent upon its forward speed through the air to create lift and make control possible. Just as a conventional plane must accelerate down a runway before it can reach flying speed and lift off the ground, so too a hang glider pilot must run down a hill into the wind to create enough airspeed to achieve flight. Once in the air, all aircraft are doing the same thing: using their forward speed to create lift. Without and engine, the hang glider (and sailplane) must always be gliding downward with respect to the air around them in order to maintain speed and lift. Only if the air around them is rising faster than they are gliding down through it can they actually gain altitude (like a bicycle with no pedals must constantly be going downhill in order to maintain its forward speed. Only if the whole hill were rising faster than the bike was going down would the bike actually be rising in altitude - yet the bike would always be going down in relation to the hill). The goal of the pilot is to find areas where a body of air is rising upward faster than the craft is sinking downward through it. By staying in such areas to gain altitude, the pilot achieves more time and distance in the air.

Meteorology is the study of weather and micrometerology is the study of weather in small, localized areas around hills or valleys and is of special importance to hang glider pilots. Although casual observers of hang gliding assume that the craft has to have wind in order to fly, this is not the case. A hang glider creates its own wind (relative wind) by moving forward through the same air, and at the time is subject to winds external to itself. The advancing hang glider pilot must learn the nature and behavior of these winds as they relate to mountains, trees, valleys and other obstacles. With such understanding, the wind can be used to gain altitude, while areas of predictable sink or turbulence can be avoided.

As a perpendicular wind hits the slope of a hill or mountain it accelerates upward and is forced t ride on the windward side. For some distance in front of thee hill it creates and area of rapidly rising air, which is used by the hang glider pilot to maintain or gain altitude. The area of rising air is called ridge lift and when the pilot enters and maintains in this air he is soaring.

Thermals are the lift created when an area of the earth's surface (such as the dark soil of a plowed field) is heated by the sun and the air above this surface gets hotter than the surrounding area. Because hot air is lighter than cold air, the warmed air mass breaks free and begins to rise. A hang glider can circle within this air mass, gaining altitude with the rising air, and this is called thermaling.

Manbirds, Hang Gliders and Hang Gliding: Maralys Wills, Prentice Hall, Inc. Englewood Cliffs, NJ. 1981.(Quoted excerpt)

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