FLYING over Alaska in the wintertime is a spectacular experience. At 35,000 feet, the state’s rugged beauty unfolds, a succession of white mountain peaks against steel-blue skies, icy lakes and frozen rivers that snake as far as the eye can see. It’s an awesome sight, wild and pristine, that glows in a thousand hues of red, orange and pink when the sun sets against the horizon.

But then, you have to land.

Juneau’s airport is surrounded by mountains, the approach often buffeted by treacherous wind shear. Sitka’s one small runway is on a narrow strip of land surrounded by water. And in Kodiak, the landing strip ends abruptly at a mountainside. The airport approach is so tricky that first officers are not allowed to land there; only captains are trusted to do so.

Doug Wahto knows these airports well. He grew up in Juneau, worked as a commercial fisherman and builder and started flying with Alaska Airlines in 1970. As a pilot, he honed the art of reading wind conditions by looking at how snow blew over mountain ridges.

Mr. Wahto retired six years ago, but not before seeing the transformation of flying in Alaska and of the airline where he spent his career. Alaska Airlines is puny compared to the major carriers: it has 124 planes, while United Airlines has more than 700 and four times as many passengers. But because of the state’s topography and extreme weather, it was the first to develop satellite guidance, a navigation technique that has transformed landing at Alaska’s tricky airports. The technique is now at the heart of the Federal Aviation Administration’s plan to modernize the nation’s air traffic system, a project that is expected to cost tens of billions of dollars over the coming decades.