GENEVA -- The extreme sport of wingsuit flying that killed British stuntman Mark Sutton this week involves a special aerodynamic jumpsuit developed about a decade ago. It creates fabric batwing sleeves around a person's arms and a flap between the legs. Wingsuit fliers also normally use parachutes designed for sky diving or jumping from fixed objects such as a building or a bridge.
How do they work?
Basically, the material functions like an artificial set of wings, giving a person's body more exposure to wind. That gives a user the needed lift and drag in the air to adjust the forward speed and fall rate. Wingsuit fliers have to arch or roll their shoulders, or move their knees and hips, to control the descent. They then open parachutes and land.
What's it like to wear one?
They can't be too loose or too tight. A loose suit means the material flaps too much while flying; a tight fit is uncomfortable and could cause a zipper to fail. There also are leg straps, chest straps and a harness, along with thumb loops over the altimeter and gloves, and emergency handles that can get accidentally covered up when the wingsuit fully opens. A person's arms have to stay parallel with their body, and legs have to remain straight with the knees locked and toes pointed.
How dangerous -- or scary -- is it?
Swiss police noted that Sutton, who doubled as a sky diving James Bond during the 2012 Summer Games' opening ceremony, was "among the best in the world" in the rarefied sport of wingsuit flying. The British Parachute Association's training manual describes the sport as "a new form of sky diving" meant for experienced sky divers who get instruction from a wingsuit coach. "For some this is an extremely scary type of jumping," it says, noting that proficient wingsuit fliers can fly horizontally at speeds of up to 235 kilometers per hour (145 miles per hour). A parachute is usually needed just one to three minutes after jumping from 4,000 meters (13,000 feet).
Are there laws or regulations?
Wingsuit flying is a gray area, reflecting the newness of the sport. Most places don't have specific restrictions on it. In Sutton's native Britain, wingsuit fliers are required to have a parachutists' certificate with at least 500 descents and other skills. The French alpine center of Chamonix, a climbers' mecca where gondola-assisted paragliders already are a common sight, tried banning the use of two main lifts for wingsuit flying last year after a Norwegian died. The ban by Chamonix's mayor called it a precaution against collisions with other aerial athletes. Just last month it was lifted, but now wingsuit fliers must first notify authorities and restrict themselves to certain hours.
Why do people do it?
Sutton, in a video of him flying last year off a wall on Switzerland's iconic Eiger mountain, said it was just "amazing" to fly in a wingsuit. One major manufacturer says its wingsuits, which cost $1,050 to $1,750, "allow sky divers and BASE jumpers (those leaping from fixed objects) to realize the dream of human flight, gliding among the clouds, to make flock formations and to swoop along the mountainside."
Are there limits to what's possible?
Time will tell. For the 60th anniversary this year of mankind's first ascent of Mount Everest, Russian extreme sports star Valery Rozov used a wingsuit to jump from the north face at a height of 7,220-metres (23,687-feet), the highest such feat so far. He also spent more than two years preparing for the stunt.