Smaller aircraft are frequently flown around for the purpose of a leisurely way to pass the time. People who are serious about this actually end up saving their money and purchasing a plane of their own that they then store at the nearest airport when not in use. However, these planes are the more traditional kinds of planes; as in, they use an engine of some sort or another to power their flight up in the skies.
Sailplanes however, also sometimes called gliders and glider planes, are a type of aircraft that have no means of artificially pushing them through the air. With no engine and a very limited amount of control over the plane’s motions, sailplanes instead glide on the strong wind currents found miles above ground. And this is one of the most fun and exhilarating activities out there, and definitely worth trying at least once.
How do Sailplanes Fly?
We’ve already mentioned that sailplanes use the wind to help them fly, but let’s dig deeper in to just how they maintain altitude when in the air. Sailplanes differ immensely in their looks and build design compared to normal traditional planes. The body of a sailplane is very narrow and long, with the cockpit being a tight fit and designed for maximum aerodynamic benefit. The wings of the glider however, are even longer than the main body. The wingspan of a sailplane is huge, and the wings are extremely slim visually. This whole slim and elongated design of a sailplane is made to ride the winds for as long and as efficiently as possible.
Due to their bodies being so light and narrow in design, sailplanes face very little drag when up in the air. Sailplanes have what is called a glide ratio. This is measured with how many miles a sailplane could glide across if starting its journey from a particular altitude. Modern sailplanes have a mind-blowingly astonishing glide ratio of 60:1. This means that if one of these sailplanes starts an unguided descent from a mile up in the sky, it can cover a staggering 60 miles before touching the ground.
Obviously, to glide for long distances, the pilot of a sailplane would first have to actually gain altitude. This is done by guiding the sailplane into pockets of updrafts of wind coming from below. There can be a number of ways and locations these updrafts can be detected and made use of. For one, any area on the surface of the Earth that get really hot under the sun heats up the air above it. Due to hot air always rushing in to fill the space occupied by colder air, this hot air is pushed up and it makes its way miles above the ground. Sailplane pilots are able to recognize areas that get hotter than surrounding places, and glide over them to make use of the updrafts of wind.
Pilots can also keep an eye out for birds that they spot gliding without flapping their wings. This is generally a pretty good indicator of a portion of the skies that is being fueled by strong updrafts of wind. Another kind of place that sailplane pilots head towards to gain altitude is any area that has hills, mountains, or other types of steep slopes. As it was explained in our post on remote-controlled gliders, wind makes its way across the Earth’s surface until it hits a slope of some sort. It then blows up the slope and up above the edge of the hill or mountain the slope belonged to. Sailplane pilots can look for these edges and ride the gusts of wind coming up from the slopes to further gain altitude.
And then there are pockets of wind that can be used to push a sailplane up that are found blowing across the tops of mountains and hills. This phenomenon is different from the one where the wind blows up a slope, and sailplane pilots often recognize these areas by the unique cloud formations found above them. This method of keeping a sailplane flying is actually quite effective, and can often lead to so much lift that the sailplane can cover the whole mountain range on this wind alone. This can be a great activity for the beginner mountain climber to enjoy.
Whenever a sailplane pilot locates any of these windy phenomena, they have to fly in to the updrafts and then keep turning the sailplane around to remain within this pocket of wind blowing upward. They do this so that they can continue to gain altitude until the desired altitude is reached. If there are multiple gliders flying together, the first one that flies in to an updraft is that one everyone else follows regarding the direction of the turn. This is a simple standard operating procedure that helps eliminate the risk of midair collision between two or more sailplanes due to miscommunication between the pilots.
In the absence of any of the above-mentioned phenomena that generate upward thrust, sailplane pilots have to sacrifice altitude for velocity. Due to the excellent glide ratios of sailplanes, a slight descent can help the plane pick up enough momentum to keep flying for very long distances. Extreme maneuvers in sailplanes are also very strictly prohibited. Unlike their much smaller remote-controlled variants that can execute some small degree of aerial stunts, proper sailplanes are designed only to glide and steep descents and other such maneuvers will likely end up with the wings of the sailplane snapping off and the plane plummeting to its very literal death.
How do Sailplanes Take Off?
With no engine to power a sailplane in the absence of forward-facing momentum, how exactly do these planes get off of the ground in the first place? To begin with, let’s first put it out there that some models of sailplanes containing a small engine powering a propeller do exist. Though the main point of flying a sailplane is to glide it across the skies without the help of an engine, some people do in fact prefer a sailplane with an engine to keep it airborne. However, there are also sailplanes out there with retractable engines. These models only make use of the engine during the initial takeoff, and then retract it inside once they are airborne.
But what do traditional sailplanes with no engines do? We discussed how a remote-controlled glider takes off in our post about tips for newcomers to gliding, and the same principle still applies to full-sized proper sailplanes, minus the part where they’re manually thrown using your hand of course. There are two main methods of launching sailplanes in to the sky that are popular all over, and then some less conventional methods that are sometimes used as well.
The first method that is used to launch sailplanes involves another traditional plane with an engine of its own. The sailplane is attached to the normal plane with the use of a specialized cable. The plane then takes off from a runway as it normally would, all the while dragging the connected sailplane behind it. Once adequate altitude to commence sailing has been achieved, the sailplane’s pilot detaches the cable and both planes turn in opposing directions to continue onwards. The pilot flying the normal plane also has an emergency detachment option for the cable in case something goes wrong.
The other method that is used quite a lot to launch – literally – sailplanes in to the sky is the winch takeoff method. In this method of takeoff, the sailplane is still connected to a cable. However, this time the second end of the cable is connected to a strong motor or engine at the end of the runway that, when activated, rapidly reels the cable in. When close to the end of the runway, the sailplane pilot detaches the cable if the plane has gathered enough altitude to successfully continue flying onward. Other, less used methods for launching sailplanes include towing the sailplane behind a vehicle till it gains altitude and throwing it off a cliff while using bungee jumping ropes. Its always important to keep an eye on the weather and maybe even have a personal weather station.
And that is all the basics of what sailplanes are and how they function. Hopefully it was enough to let you decide if you’re interested in trying it for yourself or not. It is quite a thrilling experience, but also very calming once you’ve mastered the controls. So if flying a remote-controlled glider just doesn’t cut it for you, perhaps flying the real thing might help.