A glider is a fully controllable airplane designed without an engine. Typically a glider is a less expensive lower performing than a sailplane. There are many factors which make some gliders perform better than others.
WHAT IS A SAILPLANE?
A sailplane is also an airplane without an engine but is higher performing with a better glide ratio. We will describe glide ratio later in this article. Of course this is a very simplistic explanation but included to say that in some ways the words glider and sailplane can be used interchangeably and is often based on the sleekness, performance, or beauty of a specific plane.
WHAT IS SOARING?
Soaring is the art or ability to stay up longer or fly further in either a glider or sailplane. The majority of gliders and sailplanes do not have an engine and when they are flying are gradually coasting downhill. Just some lose more altitude for each foot or mile they fly forward. There are several sailplanes which do include an engine (often hidden in the fuselage) which can be used to either gain altitude during a flight and even some which are self-launching.
Most gliders and sailplanes here in the U.S. use what is called an aero-tow to begin their flights. This is where a single engine airplane is used with a 200 foot rope attached to the glider and the tow plane pulls or tows the glider up to a pre-plannend altitude at which time the pilot or student pulls a release and disconnects from the tow plane and rope. Much of the training process is done with short flights and tows up to 1,000 feet above the ground to practice landings and some higher/longer flights to practice other maneuvers and to learn to soar. Tow costs typically range from $50 -$75 each depending on altitude and location.
In much of the rest of the world and some clubs here in the U.S. use what is called a winch to launch the glider. A winch is a car or truck chassis with a speed controllable spool of cable which is pulled out to the glider and connected to a release on the glider. When the pilot is ready the winch reels in the cable and quickly launches the glider which then climbs at close to a 45 degree angle. Depending on the location the cost of a winch launch is much less than the costs of operating a single engine airplane to tow a glider up. Since most runways and locations used for a winch launch do not have unlimited lengths of cable and space normally an aero tow can take a glider higher than a winch. There are some locations which use a car or truck using a rope to pull the glider up, like on a dry lake bed but this method is not used very much.
Getting back to what soaring is ... soaring is when you can stay up longer than a simple downhill glide back to the airport. Since the glider is always coasting downhill, if the pilot can find pockets of air which are rising faster than the glider is coasting downhill you gain altitude. So, one way to look at it, soaring is staying aloft longer than just a few minutes. There are several different weather conditions which create lifting air used to gain altitude in a glider. In most cases this lift is not directly related to the wind. Unlike what some people may think, gliders do not require a constant wind like a kite does. Once a glider is aloft it will have a downhill coast back to the ground. This is called the glide ratio and can vary from 15 to one all the way up to 50 to one, or saying it a different way, if your glider has a 15 to one glide ration and you are a mile high, you can glide 15 miles in completely still air. Or 50 to one means if you are the same mile up you could glide 50 miles before touching down. So, even if the wind completely stops a glider will still be able to land safely.
The most common lift used in soaring is call thermal lift, which is where the sun heats up the ground and the air warms up and begins to rise. When a glider finds one of these rising patches of air, called a thermal, they circle in the thermal and gain altitude and then they can fly along their intended route. Altitude gains of 5,000-10, 000 feet are not uncommon. Once you gain altitude you can then fly until you either find another thermal or a place to land. Depending on your skill and performance of your glider it is possible to stay aloft for hours or travel for hundreds of miles this way, going from thermal to thermal.
Other types of lift use the wind either against a hill or mountain range. One is called ridge lift and is where you fly close to the hill or ridge and the wind is deflected upwards, and you can fly along, often in a straight line without loosing altitude and you can go long distances. Another wind related way to gain altitude is called wave lift, which is where higher winds are blowing perpendicular to a mountain range and a standing or stationary updraft or wave is located downwind of the mountain range. These waves are like when water flows over a rock in a stream and there are waves or ripples downstream of the rock and the first few are actually higher than the rock itself. Wave lift can be used to fly to very high altitudes, the world altitude record is over 60,000 feet above sea level.
A good clear explanation.
And some simple manuvers
Bruno Vassel, from Utah, gives a tour of a competition sailplane's instruments. He as many great videos on Youtube.
Partnering with the Tucson Soaring Club and flying at The El Tiro Gliderport, west of Marana, AZ
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