HIGHLAND, Ill. – Flying high without powered flight. Most would avoid it but members of the St. Louis Soaring Association in Highland, Illinois are thrill-seekers.
"I kind of like to think of these as surfboards for the sky," said club president Patrick Brannan.
These gliders are planes designed to fly without an engine. Instead, they use the power of thermals in the atmosphere.
"When you have thermal activity, the planes are efficient enough that you can stay in a rising column of air and climb,” Brannan said. “We need sort of those popcorn clouds that look like balls of popcorn. Every little one of those is an elevator.”
These elevators allow the long-winged planes to stay afloat. This is as the uneven heating of the Earth from the sun creates for a column of rising air, lifting the plane higher up into the atmosphere. It’s important for pilots to remember: where there is lift in the atmosphere, there is also a sink, as warm air will eventually cool and fall with height.
To set sail, they must initially gain altitude with a tow plane. Typically, pilots climb to about 3,000 feet with the tow plane before releasing. After separating from the tow, it is crucial for the pilots to find the favoring conditions if they want to stay in the sky. If the plane doesn't find a thermal, they are in an area of sink. This means they are losing altitude and will be forced to land or find a thermal pocket to keep them in the air.
Pilots enlist the help of animals during their flight.
“When you look up in the sky and see some of those long-winged birds just doing a circle, they’re in a thermal; using Mother Nature’s energy and you know, ‘Yep, that's where I need to be,’" said club member Mark Ober.
The planes are designed to be efficient travelers. Gliders are made of lightweight material and designed slim, with long wings to improve aerodynamics and increase the glide ratio.
Glide ratio compares how far forward a plane will fly in comparison to how much altitude it will lose during that time if they are in an area of sink.
For example, a glider with a ratio of 30:1 means the plane will move forward 30 meters while only losing 1 meter of altitude. A typical glider has a ratio of 34:1, while the best gliders have a ratio of 70:1.
For comparison’s sake, the glide ratio of a Boeing 747 is 12:1.
To experience an engine-less flight, learn how to be a pilot, and join the club, you can visit STLsoar.org for more info.