Gravity acts on a hang glider just like on everything else, so the glider is always “falling” relative to the parcel of air it’s in. Hang glider pilots search for areas of “lift,” where the parcel of air they’re in is rising faster away from the earth than the wing is falling toward it. Ridge lift occurs when horizontal wind hits an obstruction (like a ridge, for instance) and is deflected upward. Thermal lift occurs when terrain is heated by the sun and transfers this heat to the surrounding air, which then rises. Pilots flying in ridge lift get up by cruising back and forth through the band of lift in front of the ridge. Thermals usually develop above some “trigger point” on the ground and then rise as a column or bubble of air. When a pilot encounters a thermal, he or she will fly in a circle in this region of rising air, climbing in exactly the same way as hawks and other soaring birds climb out by circling in thermals.
Posted in: General Hang Gliding FAQs