The western half of China, from Xinjiang in the north to Tibet and Yunnan in the south, is forbidding terrain. It includes some of the world’s most mountainous territory, and it is dangerous to fly over for obvious reasons: peaks, violent storms, gusty winds. But there is also a less obvious reason. The navigational tools that have let aircraft find their way through bad weather and threatening terrain, and that have let controllers monitor their progress, have long depended on installations on the ground. It is no problem to have radar stations and navigational beacons dotted at intervals of a few dozen miles all across the East Coast of the U.S.—or the East Coast of China as well. It is a huge challenge amid the mountains and high plateaus of Tibet. Radar beams and ground-based navigation signals travel in straight lines, so they can’t reach into the valleys between mountain ranges. Air-traffic controllers looking for airplanes, and pilots looking for navigation signals, are both effectively blind when a mountain sits between a radar site and the airplane.
Much of western China has thus until recently been effectively beyond the range of reliable air travel. Navigation was so difficult that planes would often fly only in clear, calm weather—and the weather was rarely clear or calm. GPS offered the first prospect of guidance to remote areas without building a network of radar stations and beacons along the way. The more recent advent of the high-precision systems collectively known as required navigation performance (RNP) is almost as important in allowing safe (and fuel-efficient) approaches, in any weather, to the most isolated and forbidding airports in the world. Naverus, a small company based outside Seattle that is now part of GE, has played a major role in the opening of these western Chinese airports. This is another illustration of the underpublicized integration of the U.S. and Chinese aviation systems.
In the 1990s, Alaska Airlines captain Steve Fulton worked with the FAA and Alaskan officials to design the first RNP approach in the world. It was for the Juneau airport, which is so closely hemmed in by mountain ranges that in bad weather (which is frequent), it was all but unapproachable. Traditional navigational systems were not precise enough to keep airplanes clear of the mountains as they dropped down toward the runway. Since no roads connect Juneau with the rest of Alaska or North America, the frequent airport closures were a big problem. Fulton’s new RNP approach for Juneau, which plotted out a precise set of waypoints for the airplane’s autopilot to follow as it wound its way through treacherous terrain, allowed safe descent through clouds and served as a proof-of-concept for making other “impossible” airports more accessible. Soon he and his team had applied 30 more RNP approaches for Alaskan airports.
In 2003, with another Alaska Airlines captain, named Hal Andersen, and high-tech entrepreneur Dan Gerrity, Fulton founded Naverus to develop RNP approaches for other airports in difficult terrain. They won contracts in Brazil, Canada, Australia, New Zealand and the U.S. But they were determined to make inroads in China. When I first met the Naverus people, in Beijing in 2007, they had just completed one historic project and were preparing for another. The achievement just behind them was an approach to what was then one of the highest and most difficult airports anywhere on Earth: Linzhi, in Tibet. Linzhi’s runway was at 9,670 feet of elevation, about the same as the highest airport in North America, in Leadville, Colorado. But Leadville is a tiny ex-mining settlement of perhaps 2,000 people, while Linzhi is a major conurbation of the Tibetan plateau. For about 300 days of the year it rains in Linzhi, and the rest of the time the weather is still rarely good enough to land under Visual Flight Rules, or VFR, which require enough visibility that pilots can find their way without instrument guidance through the 18,000- to 20,000-foot escarpments alongside the narrow valley in which Linzhi sits.
Lhasa is the next airport to the west, 200 miles away. Bangda, an even more remote Tibetan setting that has the highest-altitude commercial airport in the world, is about 200 miles to the northeast. Because the surrounding territory is so impossibly steep, only a few light airplanes had ever landed at Linzhi; no “transport aircraft”—airliners or cargo planes—had ever touched down on its runway. As with so many infrastructure projects in China, the big, new Linzhi airport with its broad runway had been built first, with practical questions about its feasibility coming second. “They just picked a location and built an airport,” Fulton told me in Beijing. “Only after that did the operational people look around to see whether anyone could actually fly there.”
After Fulton and his team persuaded Chinese aviation officials to let them try an approach for Linzhi, he got his first in-person look at it. He flew to Lhasa and made the 10-hour drive eastward, by way of twisty mountain roads, to Linzhi. The airport itself proved to be beautiful and modern, with a long, well-paved runway. But the terminal was practically vacant. “They had their fire trucks, their jetways—but no action,” he said. His next step was to use his own handheld GPS to begin making precise measurements of the location and elevation of significant areas around the airport. Foreigners are in theory forbidden to do this kind of mapping in China, because of holdover national-security concerns. Fulton explained that he had to make the measurements because the official Chinese maps were so imprecise or wrong. “Through this process, I think the Chinese themselves began to see the importance of accurate terrain information,” Fulton said. “If it’s wrong, you crash.”single page
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