Paragliders

Gliders The paraglider wing (or ‘canopy’) is a self-inflating structure consisting of a row of cells, most of them open at the front and all of them closed at the back, joined together side by side. Moving through the air keeps them inflated because air goes in the front but can't get out the back. In cross-section, the cells form anaerofoil cross-section to produce lift, just like an airplane wing. The pilot is supported underneath the wing from a web of lines (each with the strength to support the pilot). The lines are then attached to strap-like risers that are attached to the pilot'sharness. Controls held in the pilot’s hands, which pull down the trailing edge of the wing, are used to control speed and to turn. The pilot is strapped into the bucket-seat harness, which holds a reserve parachute, and includes a ‘speed system’ which pulls down the leading edge for maximum flying speed. All recreational harnesses have a foam or air-bag back protector. Solo paraglider wings typically have an area of 20–30 m2 with a span of 8–12 m, and weigh 4–7 kg. Combined weight of wing, harness, reserve, instruments, etc is around 12–16 kg. Glide ratio is typically around 8:1 (compared with 15:1 for hang gliders and 60:1 for sailplanes), and speed range is typically 20–50 km/h (stall speed – max speed). Modern paraglider wings are made of high-performance non-porous fabrics such as Porcher Marine & Gelvenor, with dyneema, superaram, or kevlar lines. For storage and carrying, the wing is folded into the harness seat, and the whole stored in a backpack (which is normally stowed in the harness in flight). Tandem paragliders, designed to carry the pilot and one passenger, are larger but otherwise similar. Flying In unpowered flight, rising air is needed to keep a glider aloft. This rising air can come from two sources: When the sun heats features on the ground, columns of rising air known as thermals are generated When wind encounters a ridge in the landscape, the air is forced upwards, providing ridge lift. In mountainous environments, flying is mostly based around thermals, which can be used to stay aloft before heading for a landing field below the launch site. In hill environments, ridge lift is used forridge soaring , and landing can be done either back at the launch site, or at a landing field at the bottom of the ridge. In either case, more experienced pilots can use thermals to go ‘cross country’.