What is soaring?
Soaring (sometimes called gliding) is the art of using air currents to maintain extended flight. On a good day a soaring pilot may fly on these currents for hours.
What is a glider, or a sailplane?
A glider is a high performance motorless aircraft which is designed to have a
very flat glide angle. This is expressed as a ratio - for example modern gliders
are being made with a glide ratio of up to 55:1.
In other words in still air it can fly 55 ft (m) forward and only lose one foot
(meter) in altitude. By contrast, an average light powered plane has a glide
ratio of about 10:1 with engine off. The average glider flying today has a glide
ratio of about 40:1 to 45:1.
Are sailplanes and hang gliders the same?
No! Most hang gliders are open designs with a poor glide ratio. A sailplane is constructed as an airplane, has an excellent glide ratio and a large wingspan. All occupants sit in comfort in a fully enclosed cockpit. Sailplanes are licensed and inspected by the FAA.
Just how can a sailplane fly without an engine?
Sailplanes are very efficient aerodynamically. In still air, a well designed sailplane will only descend at a rate 125 to 150 feet per minute. If the air in which the sailplane is flying is rising at exactly the sailplane's natural descent rate, the sailplane will remain at the same altitude. If the surrounding air is rising faster than the sailplane's natural descent rate, the sailplane will actually gain altitude.
How much control do you have over a glider?
The glider has conventional directional controls just like any other aeroplane,
and the pilot has complete control over where he is going. The motive power
however, is provided by gravity, just like a car coasting down-hill. In the
glider, the pilot has control over the steepness of the "hill", and can point the
nose down to go faster, or up to go slower. If the nose is raised too much, the
speed will reduce to the point where there is not enough airflow over the wings
to generate lift, and the glider will "stall". if this is not corrected by
promptly lowering the nose, a spin could develop. This is also easily corrected,
but of course a well trained pilot does not allow such things to happen! To keep
flying, the nose is always pointing slightly down.
What is a thermal?
When the sun warms the surface of the earth and the upper air is cooler than the ground, warm air currents rise to meet the cooler upper air. At this time they form cumulus clouds, big puffy fair weather clouds. Sailplanes often follow these clouds to an altitude of 5,000 feet or more.
What causes the air to rise?
There are three primary sources of "lift" utilized by sailplane pilots. The most common is thermal lift, formed when air, warmed by the ground, rises. No wind is required to form thermals. The second form of lift is ridge lift, formed when wind strikes a mountain ridge and is forced upward. The third form of lift is mountain wave, formed when wind moves in great waves on the lee side of a mountain, just as water ripples behind a stone in a stream.
What happens to a sailplane when the wind quits?
It is true that sailplanes often gain additional altitude or lift from the wind; however, the wind need not be blowing for a sailplane to fly. For example, thermals, an important source of lift, often form best when there is little or no wind.