Jump. Fly. Land.
Jeb Corliss says if the birds can do it, so can he.
- By Carl Hoffman
- Air & Space magazine, November 2010
The dream has recurred since childhood: I jump, and I can fly. I’m amazed. There are no awkward flapping wings, no roaring engines, no hang glider over my head. Just me flying, pure and delightful. I’m up and whizzing over the landscape, and it’s as simple as that.
“Flying in a wing suit is that dream!” says Jeb Corliss. “It’s the closest you can come to real human flight.” At home in Venice, California, Corliss is barefoot and dressed in black pajama-like pants and a black T-shirt. His head is shaved, and he’s tall and lanky—a bit stork-like. He grabs an iPad and flicks it with his long fingers and there’s a video of men—in weird stretchy suits that make them look like giant flying squirrels—streaking through the air five feet over sawtooth ridge tops and banking along stony cliffs, and all I can think is: It’s my dream come to life.
The modern wing suit was born in the 1990s, and ever since, wing suit fliers and designers (they are for the most part one and the same) have been nurturing that dream, extending the glide ratio of the free-falling skydiver or BASE jumper (an acronym for Buildings, Antennas, Spans and Earth’s natural features, like cliffs). They’ve pushed it to a bit more than three miles forward for each mile in lost altitude, abetted by high-tech fabrics and “wings” that channel in-rushing air to create lift.
Alas, a chute must always be deployed. But what if you could jump from the sky and fly through the air and land, just like a bird? Corliss sees that as the purest form of human flight. He wants to be the first person to jump out of an airplane and land safely without a parachute, and make it repeatable. The plan has a lot of ifs, and the biggest is money. He needs about $3 million to erect, in the middle of the Las Vegas strip, a ramp hundreds of feet tall. It would look like a ski jump, but act as a landing slope. Since Corliss would bellyflop on it head forward, arms back, he’s found it difficult to persuade people with deep pockets to finance what, after all, could become a televised suicide.
The notion of fatality aside, however, any discussion about landing without a parachute has to start with this fact: Ever since the invention of the airplane, a few people have fallen out of the sky without parachutes and lived to tell the tale. Nick Alkemade, a Royal Air Force tail gunner, jumped from his flaming turret in 1944 without a parachute and fell 18,000 feet into Germany. When he came to, he saw stars overhead and, with no more than a sprained leg, lit a cigarette. Alkemade’s luck? Fir trees, underbrush, and snow. Three decades later, a terrorist’s bomb blew up a DC-9 flown by Yugoslavia’s JAT airline, and Serbian flight attendant Vesna Vulovic fell 33,000 feet. She landed in snow and lived. There have been others. Roy Haggard, a longtime aerospace engineer and chief technologist at Hunter Defense Technologies in Solon, Ohio, says, “If it’s been done by accident with an incredibly low probability of success, well, it just becomes an engineering problem, and not a stunt, that in fact has a statistical probability of success.”
AT THE HEART of Corliss’ plan lie the challenges inherent in the human body’s design. While even large birds are light as a feather, with hollow bones and long, wide wings, humans are dense objects, with long, heavy legs and short, heavy arms—and no wings. Corliss recites a history starting in ancient times of wingnuts who jumped from buildings, often to their deaths. Today, the closest thing to pure flight remains a hang glider. It avoids the problem of our physiology with a set of big, relatively rigid wings. When the first modern wing suit flier, a French skydiver named Patrick de Gayardon, created a nylon jump suit in the mid-1990s with fabric between his legs and extending from his wrists to his waist, with open cells that gathered air, he suddenly had the first suit that served as an airfoil. De Gayardon managed only a 1:1.3 glide ratio, little better than a skilled skydiver in freefall. He died in a fall in 1998 when a new packing method he was trying for his rigging caused it to fail, and left unrealized his dreams for the potential of wing suits.
A year after de Gayardon’s death, a Croatian, Robert Pecnik, became the first person to manufacture and sell wing suits. Over the next decade, surface area increased. The wings of today’s suit extend from the wrists to the ankles. Short of adding appendages to the human body, designers cannot add surface area. This is where wing suit art and wing suit science collide. Using wind tunnels for research is difficult because the dummies would be static and rigid, whereas real wing suit flying involves humans flexing muscles and moving the hands, arms, legs, feet, and head. Also, the tunnel’s air stream flows in one direction, while a wing suit flier is dropping and moving forward. And a theoretical test body, a mannequin, has to be scaled to exactly 40 percent of the diameter of the tunnel to get the right air flow. The wing suit community is so small—maybe 600 worldwide, Pecnik estimates, with a mere 40 or 50 who “proxy,” or fly close to cliffs and buildings—that there’s just not enough money for the kind of research that might significantly increase glide distances.
All of which means that Jeb Corliss, flying the best suit money can buy (about $1,500), will be hurtling downward and forward hard and fast. He’s got lift, for sure, but he’ll be traveling at more than 100 mph, dropping a foot for every three feet forward. It’s the maximum glide angle, and one at which he can’t get more lift; he can’t suddenly flare up while screaming in toward a landing. “An airplane comes in at a certain approach speed and the pilot pulls the stick back and flares, and that neutralizes the sink rate,” says Mark Maughmer, a professor of aerospace engineering at Pennsylvania State University. “You’re trading the airspeed you have, its kinetic energy, into potential lift for a moment.” But Corliss will have precious little flare. Which is why wing suit fliers on proxy flights don’t, in fact, go for maximum glide angle, so they have a little something in reserve in case they need to swoop over and away from objects. Corliss, then, will travel even faster, and that’s the essence of the challenge: Come in for a landing so fast with so little lift that his abort options are extremely limited.