Ridge soaring In ridge soaring, pilots fly along the length of a ridge feature in the landscape, relying on the lift provided by the air which is forced up as it passes over the ridge. Ridge soaring is highly dependent on a steady wind within a defined range (the suitable range depends on the performance of the wing and the skill of the pilot). Too little wind, and insufficient lift is available to stay airborne (pilots end up ‘scratching’ along the slope). With more wind, gliders can fly well above and forward of the ridge, but too much wind, and there is a risk of being ‘blown back’ over the ridge. When ridge soaring, it is usually possible to either ‘top land’ or ‘slope land’ close to the launch site, which saves time returning from a landing site back to the launch site. Thermal flying When the sun warms the ground, it will warm some features more than others (such as rocks or factories), and these set off thermals which rise through the air. Sometimes these may be a simple rising column of air; more often, they are blown sideways in the wind, and will break off from the source, with a new thermal forming later. Once a pilot finds a thermal, he or she begins to fly in a circle, trying to center the circle on the strongest part of the thermal, where the air is rising the fastest. Most pilots use a ‘vario’ (vario-altimeter), which indicates climb rate with beeps and/or a visual display, to help ‘core-in’ on a thermal. Good thermal flying is a skill which takes time to learn, but a good pilot can often follow a thermal up to cloud base. Cross-country flying Once the skills of using thermals to gain altitude have been mastered, pilots can glide from one thermal to the next to go ‘cross-country’ (‘XC’). Having gained altitude in a thermal, a pilot glides down to the next available thermal. Potential thermals can be identified by land features which typically generate thermals, or bycumulus clouds which mark the top of a rising column of warm, humid air as it reaches the dew point and condenses to form a cloud. In many flying areas, cross-country pilots also need an intimate familiarity with air law, flying regulations, aviation maps indicating restricted airspace, etc. Launching / landing As with all aircraft, launching and landing are done into wind (though in mountain flying, it is possible to launch in nil wind and glide out to the first thermal). In low winds, the wing is inflated with a ‘forward launch’, where the pilot runs forward so that the air pressure generated by the forward movement inflates the wing. In higher winds, a ‘reverse launch’ is used, with the pilot facing the wing to bring it up into a flying position, then turning under the wing to launch. In flatter countryside, pilots can also be launched with a tow. Once at full height, the pilot pulls a release cord and the towline falls away. This requires separate training, as flying on a winch has quite different characteristics from free flying. In many countries only towing from a stationary winch is permitted: ‘static’ towing, with a fixed length towline attached to a car, is far more dangerous. Control of the glider The pilot holds controls in each hand which pull down the trailing edge of the wing. Pulling down the trailing edge increases theangle of attack of the wing from its ‘trim’ (hands-off) position, which slows it down (like flaps on an aircraft wing). Turning is achieved by a combination of pulling down the control on one side, and ‘weight shift’ within the harness. Faster than ‘trim’ speed can be achieved by pushing out a ‘speedbar’ with the feet, which pulls down the leading edge to reduce the angle of attack. On occasions when it is necessary to lose height more rapidly, the outer part of the wing can be ‘folded in’, in what is known as ‘big ears’. This reduces the flying area of the wing, effectively reducing theglide ratio. In more extreme conditions, other manoeuvres such as ‘b-line stalls’ and spiral dives can be used, but most pilots avoid getting themselves into situations where these are required. Collapses In turbulent air, since the wing is not rigid, part of the wing can collapse. On modern recreational wings, such collapses will normally recover themselves without pilot intervention. For the rare case where it is not possible to recover from a collapse (or from other threatening situations such as a spin), most pilots carry a reserve parachute. Thankfully, most pilots never have cause the ‘throw’ their reserve. Disciplines
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