McKinley is deadly, but ‘they keep coming . . . ‘ : The mountaineering season has started on the continent’s highest peak; 11 perished in 1992.

The helicopter intercom pops with nervous voices:

“93% . . . 96% . . . 103% . . . I can’t see a thing. . . . Me either. . . . Don’t like this one bit! . . . Nope! . . . Kerthunk. Kerthunk.”

Translation: The twin-rotor Army Chinook CH-47, flying over the Kahiltna Glacier on North America’s mightiest mountain, is attempting to land search-and-rescue supplies. But as it makes its approach, its twin turbine engines are torqued beyond their safe capacity at this high altitude.

Before the heavy, underslung load touches the ice, the helicopter kicks up a fury in the 15 inches of new fallen snow and the ship is engulfed in a blinding whiteout of its own making. The pilot nurses the shuddering machine slowly upward and turns in a circle, to try again.

After four attempts, the “kerthunk” is the sound of a fast beating heart, no doubt--if you are aboard--your very own.

It’s springtime in Alaska; the 1993 mountaineering season is getting under way on Mt. McKinley. And here, even a routine maneuver like ferrying stockpiles of rescue gear by helicopter to the 7,200-foot base camp (temperature 10 below) and to the 14,200-foot rescue camp (27 below) is a struggle.

Last year was the most crowded and deadliest in the long mountaineering history of McKinley--known to many by its Indian name Denali, the High One. In 1992, 1,070 climbers tried the mountain from 10 different routes during a 90-day season; 512 made it to the summit, 11 died.

“And now, here they come again,” says John Quinley of the National Park Service, which has jurisdiction over the central Alaskan mountain. “A typical year on McKinley sees people die and people get hurt. And they keep coming.”

Standing 20,320 feet tall just south of the Arctic Circle in the path of fresh-brewed arctic storms, McKinley is probably the coldest of the world’s great mountains. Surely, it produces some of the most extreme weather on the planet. Storms can last two weeks with winds over 100 m.p.h., temperatures of 50 below and wind chill off the chart.

Today the growth of two phenomenon--international adventure travel and McKinley’s mighty reputation--combine to create a lure that mountaineers understand but others might not.

“Many people died last year, so more are coming now,” explains glacier pilot Jim Okonek. His bookings at K2 Aviation are up 25% to fly climbers into the base camp area where most three-week-long expeditions are mounted.

This past weekend was the official opening of the climbing season, a time when the days are growing longer, when the worst of winter weather is subsiding and before the summer sun weakens the snow underfoot.

In preparation, the U.S. Army and the Park Service teamed up recently to supply the base camp with emergency aviation fuel and the rescue camp with 5,000 pounds of survival and medical gear and food and even custom-sewn oversized body bags.

“Bodies we get usually aren’t in natural positions--they’re frozen and arms and legs are poking out where they shouldn’t be,” says J. D. Swed, chief ranger for the mountain and a search-and- rescue expert.

Those who know Swed and his team of high-altitude rescue mountaineers said last year’s disastrous season was particularly wearing for three reasons: A colossal 11-day-long storm killed seven. A friend and popular local guide, Terrance (Mugs) Stump, fell into a crevasse and could not be saved. And a large contingent of South Korean expeditions got in over their heads and forced some harrowing high-altitude rescue attempts.

Three Koreans in one party camped on a snow bridge over a crevasse in a storm only to have the bridge collapse underneath. They were rescued, although one who became wedged deep in the ice figured it was hopeless and tried to hasten his death by repeatedly biting the only thing he could move, his tongue.

Since then, Swed has traveled to Korea to try to familiarize mountaineers there with the hazards on McKinley, which has a greater vertical rise from base-to-top than any mountain, including Mt. Everest. McKinley begins at 2,000 feet above sea level and rises 18,000 feet to its peak, while Everest emerges from a 17,000-foot-high plain to its peak of 29,028 feet.

But the weather and the crevasses and the judgment calls and luck and the other countless but crucial vagaries of mountaineering--well, there is nothing Swed can do about those. He waits and listens to his emergency shortwave radio, which he carries like a baby. And he watches the weather.

Small dots here and there on the mountain, wrapped in nylon and packed in down, are the year’s first climbers, dragging supply sleds up the approach glaciers to the rock cliffs that lead onward to the most famous landmarks in American mountaineering--names that raise gooseflesh, haunt the nightmares and fuel the dreams of those who know, the West Buttress, Windy Corner, the Cassin Ridge, Denali Pass, the Archdeacon’s Tower. And of course, South Peak, the top of the continent.