»What you don't see: To scout a jump, Holden might rappel down a cliff or snap a Polaroid of his line. For this one, though, he hovered above the cliff in a helicopter to gain perspective. The prep work keeps him calm. "In my mind, I'd already skied the line," he says. "I was comfortable with my vision."

»"You gotta know your slough management." So sayeth Holden. Starting atop a 50-degree slope 1,500 vertical feet above his launchpad (photo 1), Holden's immediate threat is the avalanche of snow cut loose by his edges, which could take him out at the ankles and whisk him over the edge. "If you're in the slough, you gotta point it," he says. "Get out in front and then start deeking"—ski down helter-skelter, constantly diverging from the fall line and changing speeds.

»Takeoff: Holden needs to be moving at a minimum of 12 mph to travel 30 feet out and clear the wall (photo 2). Seem slow? As soon as he's in free fall (photos 3-5), he'll be accelerating at the rate of 22 mph per second.

»Halfway there: 75 feet down and 1.82 seconds into free fall (photo 6), he's traveling at 49 mph. The wind rush could easily rock him backward into a lethal reverse somersault. "I'm looking at my landing, keeping my hands out in front, staying over the front of my skis," Holden says. "Once you're in the backseat, she's pretty hard to recover."

»The 80-foot rule: With an elevator-shaft drop like this, trying to stick it—land without falling—gets very risky after 80 feet (photo 7). "Your knees will buckle, and you'll probably blow them up," says Holden. To avoid that, he will take the hit in a four-point progression: skis, knees, butt, back. "You gotta lay it out," he says. "If you try to stick something that big, you'll blow your knees through your face."

»Constant acceleration: At 100 feet, Holden's going 55 mph and gaining (photo 8). While sky divers in the "arch" position can expect to reach terminal velocity (the point at which air resistance stops acceleration and an object falls at a steady rate) at 130 mph, a skier falling feet-first is far more aerodynamic and would continue to accelerate for hundreds, if not thousands, of feet.

»The crater: Holden hits the snow going 62 mph. If he landed on solid rock, the impact forces would be in the neighborhood of 1,840 pounds, the equivalent of jumping from a 15-story building and sufficient to break every bone in his body. His fate lies with the snowpack. A 45-degree slope lengthens the impact time to 0.75 seconds, reducing impact forces to 675 pounds, which he can handle if he crash-lands correctly. "You want deep snow, but not bottomless fluff you'd blast right through," he says. Holden lands according to plan, hitting all four points. Pushing himself out of the crater, he skis off, mind and body intact. —M.P.

photos: Dave Nagel/Points North Heliskiing