At any moment, there are between 50 and 60 airplanes stacked up in the sky over Moscow. Someone has to keep them from meeting on less than friendly terms.


That job falls to the Moscow Air Traffic Control Center, housed in a nondescript building adjacent to Vnukovo Airport. There, 650 dispatchers steer approximately 1,500 planes a day across a wedge of air the size of France and Italy combined.


It is the kind of job that can be tough on newcomers. Ushering the population of a small town through the air above Moscow every day is ripe nightmare material.


"In the first few weeks, all you can think about is the fact that a single mistake can have enormous consequences," said Vladimir Yegorov, director of regional traffic at Moscow Center. "I mean, there are people up there."


Never mind that the rooms of Moscow Center are draped in soothing blues and bathed in soft lighting. You can still break a sweat, and don't count on the stress dissipating with time. "For the first 10 years, you dream about work," Yegorov said.


So one thing you know about life as an air traffic controller is true -- it gets tense. But forget everything else you saw in "Airport." Most controllers, or dispatchers, as they are called in Russian, do not work in towers. They do not sit in the dark. And they are not cramped cheek to jowl, noses pressed to their radars.


The nerve center of Moscow Center is a series of cavernous, well-lighted rooms with rows of modern, Western radar equipment spaciously arranged in tidy rows.


The building's ground floor contains two divisions, one for traffic flying over Moscow and another for flights approaching the city's four commercial airports.


Once flights are on their final approach, Moscow Center hands them over to the airport control tower. The center also handles military flights and traffic in and out of smaller airports in the region. A total of 300 airports fall under its jurisdiction.


The work environment appears relaxed. Between flights, controllers chat back and forth and swivel about in their seats. Make no mistake, though. When the radio crackles with a signal from the sky, everyone snaps to attention.


But these days, the radio is crackling less frequently. Shortly after the collapse of the Soviet Union and the disintegration of national carrier Aeroflot, air traffic dropped precipitously. In 1990, Moscow Center handled nearly 3,000 flights a day. Now the number is half that.


"Of course, the fewer flights you have in the sky, the easier it is to direct them," said Vasily Kustov, deputy director of Moscow Center. "But this is a temporary phenomenon. I think that in 1995 and 1996, we will see things on the order of 1990, when our abilities were pushed to the limit."


Whether the center is at full capacity or not, the work is strenuous and intense. Every day, between 600 and 700 flights land in Moscow -- roughly a flight every two minutes.


It can get to be a bit much, which is why Kustov advises passengers to focus on the latest best-seller. "Really, it's better not to think about these things," he said.


Leave that to the folks on the ground. Moscow controllers work eight hour shifts and take 20-minute breaks every two hours to smoke a cigarette, listen to music, or even go for a jog. Watching television is prohibited, because staring at a screen is the last thing an air traffic controller needs to do on a break. Kustov wouldn't say how much Moscow Center controllers earn, but said they make less than their Western counterparts and more than the average Russian salary.


The work is hard, but popular. "As far as employment at the Moscow Center, there is no shortage of people who want to work here," Kustov said. Applicants are subjected to tests that probe everything from their reaction time to the amount of adrenaline in their blood during stress.


"We want to make sure that when the going gets tough, people don't start crying for their mother," Yegorov said.


An air traffic controller, he said, "is like a ballerina." They both have to be in top form -- physically and emotionally -- to perform.


Alexander Zhivov, 28, has been an air traffic controller for eight years, said he handles the stress well. "At my age, I notice it very little," he said. And then he glances around at his colleagues, who have a few years on him. "Maybe if I were older, I'd handle it differently."