The ride begins, and you feel a jolt as you begin to rise, but it subsides, and all you feel is the acceleration as you ascend into the sky, the view getting better, the noises of the ground falling away, your daily routine left far below you in the dirt.

Birds fly by, and instead of watching them cruise away, you turn to follow them, hitting an updraft of warm air called a thermal, and rising again. Two ear holes cut into your motorcycle-like helmet allow you to hear the wind swirling around your head. After anywhere between 20 minutes and 2 hours later, you touch down back on terra firma, ready to do it all over again.

Cupertino resident David Cherne does this at least three times a week.

"It's the feeling of exhilaration--I feel like I'm addicted to the sport--and I've never felt as strongly about a sport as I do about it," he says. "It's really hard to describe the feeling; there's just something about doing it that sucks you in."

Cherne, 42, is part of a small local community of hang-glider and paraglider pilots in the Bay Area who regularly go running off cliffs, hills and other launch points to defy gravity for short periods of time.

"I've always had a dream of flying," fellow pilot and Cupertino resident David Olszewski, 35, says. "As a kid, I saw people flying remote-controlled airplanes and I wanted to do it, and I love to watch birds fly."

Paragliding, where a pilot is harnessed to a parachute-like wing and has to run forward to get airborne--much like an airplane must gain speed on wheels first--began in Europe as a means of descending from mountains after a climbing expedition.

It began taking off in the United States in the early 1980s, as a more compact, convenient alternative to hang-gliding--which became popular in the late 1960s and '70s.

Unlike hang-gliding, which uses a rigid wing supported by a frame, with the pilot hanging below, paragliding suspends the pilot in a harness or sling below a modified parachute. Paraglider pilots do not achieve the same speed as hang-glider pilots, but the paraglider folds up neatly to be carried like a backpack, so pilots can hike to launch sites and fit their gliders in small cars. For a hiker like Olszewski, flying out of Ed Levin County Park means he first gets to do a three-mile, 1,700-foot climb up to his launch site and then launch off.

In addition to being a hiker and pilot, Olszewski is also a scuba diver and says he gets some of the same feelings from the two sports.

"When you dive, you float in the water, and when you fly, you float too, but in a different medium," he says.

And just as Northern California is home to some of the best scuba-diving sites in the world, Cupertino--and the Bay Area--is surrounded by ideal flying sites, from the sand dunes in Seaside to the sprawling hills of Ed Levin County Park in Milpitas. Coastal areas provide for ideal "ridge soaring" sites, where pilots can fly for hours on the updrafts coming from the Pacific Ocean, and inland sites like Ed Levin or Mt. Diablo provide for "thermalling," the name Cherne gave to the practice of flying over land using updrafts to stay aloft.

"I enjoy coastal flying, but I definitely prefer thermal flying, because it's more challenging to find the thermals to keep yourself up," Cherne says. "There's just something about catching a thermal and going up that I enjoy more than just ridge flying."

Being self-employed, Cherne's job allows him to indulge his addiction more than most pilots--Olszewski works five days a week in Silicon Valley--but both agree that they need to fly to be happy and healthy.

"I'm an IT professional, so I pretty much stay inside in an office during the week, so it's good to get outside when I can," Olszewski says. "It gives me something that I need, that I don't get during the week. I get to do something completely different from my usual routine."

He got into the sport two years ago to finally achieve his dream of flight.

Cherne found it just under two years ago with his brother. The two men got certified together in Flagstaff, Ariz., and have flown around the world together.

One of Cherne's greatest flying memories is flying with his brother at the end of a long day in Austria and landing in the yard of the cabin they shared with their wives. The women--who had been skiing in the mountains all day--were waiting for the pilots with beers in hand.

While there isn't always a beer stein waiting for him at his landing site, Cherne prides himself on his "spot landing" ability. He's competed in several competitions, and placed as high as second in some of them. He says that half of the time, he can land within 10 feet of his chosen landing site, and he continues to practice to get that percentage higher.

In addition to working on his landing abilities, Cherne says he constantly works to get better at identifying thermal updrafts to improve his flying time and distance.

"It seems to be a skill that you develop over time, and it seems that there are always things you can be learning in this sport," Cherne says.

In his life as a paraglider, he has logged more than 200 hours and earned his "P4" rating, meaning he is an advanced pilot.

In his brief piloting career, Cherne says he has traveled around the Western United States and Mexico in search of new skies to fly. While he has made friends with fellow pilots, he says he will not push his friends to get involved in the sport.

"I would love to have my friends get involved, but I want them to choose to do it on their own. I wouldn't want to push them into it and then feel responsible should something happen," he says.

Those who decide to take up the hobby usually take lessons to become certified hang-gliding or paragliding pilots with the U.S. Hang-Gliding Association--which paragliding recently became a part of. The licenses, which have five levels to them, indicate that a particular pilot has logged a certain number of flight hours and can skillfully execute a certain number of maneuvers. They are rated "P1" through "P5" for paraglider pilots and "H1" to "H5" for hang-glider pilots.

Depending on how dedicated one is, someone can get a beginning pilot's license in only five days or in as long as five months.

Unfortunately, however, some people don't get licensed at all and don't learn how to fly safely. Training with a certified instructor will ensure that individuals understand the importance of preflight checkups and how and when to launch and use their gliders.

Santa Clara County Senior Park Ranger Jeff Cossins is one who knows the importance of safety.

Cossins says he sees the pilots at Ed Levin almost every day. And he sees a number of accidents, mostly minor, on a yearly basis.

"We have several accidents here a year, but nothing really bad," the ranger says. "The last substantial accident we had was a midair collision a few months back. But even then it wasn't so bad. The people involved in it are both flying again."

Nonetheless, this is a hazardous sport.

"There's always some excitement when I fly, but it's a calculated risk," Olszewski says. "The adrenaline is what makes it so addictive."

But the sport doesn't come cheap.

Much like scuba diving, Olszewski says there are high up-front costs for the sport, one-time fees to buy equipment that can run a pilot between $3,500 and $5,000 for the paraglider, safety equipment, clothing and maintenance.

But, he says, the equipment can last a number of years, so the investment goes a long way. The biggest threat to a properly cared-for glider is the UV damage from sun exposure, but that is just part of natural wear and tear.

But there's one necessary ingredient for flight that can't be bought from any outfitter--the wind. That's where "Debbie" comes in.

Ed Levin Park operates a "wind talker" nicknamed "Debbie," which is an automated telephone service that provides the current and recent wind conditions for the park. People can call into the service to get an idea of how the winds are blowing before they leave home.

Even if winds are good when a pilot calls, they can quickly change, grounding gliders and turning paragliding and hang-gliding into social activities.

"The social aspect--at least for me--plays a role when conditions say you can't fly for whatever reason, because you at least have someone there to talk to," Olszewski says.

While pilots can fly during any season, various sites are better in certain parts of the year. For example, on the coast--where Olszewski prefers to fly--summer months are hard because of heavy fog.

Both men say they plan to keep flying as long as they can--which may be several decades, because some pilots they know are in their late 60s--as long as there is gravity to escape, thermals to catch and birds to hang out with.

For more information on paragliding or hang-gliding, visit www.ushga.org. For local information, visit www.hang-gliding.com.

Martin Nobida contributed
to this story.