The room is dark and close. It shuts out the day, so what light there is is not natural. It glows from the nine radar scopes lining the walls. A man sits at each, wired into the phosphorescent sweep of the antennae.

The air conditioning hums, muting the voices of men who speak in code. "Allegheny one six one fly to zero four zero, intercept to zero seven two." Digits spin in a clock set into a bank of gauges: 12:08. That's Greenwich Mean Time; so it is a little after 8 in the morning when -- in the words of one man here -- "the monster wakes up."

The monster is National Airport.

At one of the scopes sits Charlie Shelleman, age 43. He has been an air traffic controller for 20 years. At this hour he is handling east departures. In 60 minutes he will rub his eyes and take a rest. Soon after he will return to guide east approaches. In the afternoon he will be up in the tower. Coffee breakes come often in this job; variety is vital.

Shelleman was in the Air Force in Europe where he eyed radar scope at American airbases. If a foreign-looking blip appeared he would radio for jets to go up and intercept.

He came home and went to school for a year. Then he "got hungry." He worked in a Baltimore brewery and then for a defense contractor, "bucking rivets" in missiles. That was leading nowhere. He applied for work as a controller; his Air Force experience gave him an edge over the competition.

Groups of digits pepper the scope. Each denotes a plane with a flight plan. Shelleman's job is to pattern this swarm of data into something safe and fast. "This is a basket-weaving operation. I have to top the man at Andrews (Air Force Base) but stay under our arrival man. There's a lot of teamwork involved." He has to shepherd jets to the airlanes that run like highways across the sky. He has to funnel planes to a safe landing at National. And he can't forget that the Cessnas, DC-4s and jumbo jets filling the air don't fly at exactly the same speeds. "Everyone's trying to figure out how to get more planes in the same amount of space." He adds, "It doesn't seem like the equipment is keeping pace with the need."

Shellman admits that all this pushing of planes, as he sometimes calls it, has taken its toll. "I can feel my reflexes slowing down a little. My nerves probably aren't what they used to be." But he also believes that controllers are a breed apart -- and that their selection is natural and true. "This isn't for the person who's looking for the average job. For a couple of hours things will be quiet, then all of a sudden you've got planes all over you like mosquitoes."

Shelleman has seen his share of young and eager men retire "on medical" -- ailments such as hypertension and ulcers having gotten the best of them. "You've got to let the job drop right here. I don't go home and have bad dreams. I do go home and have my cocktail. I work hard, I play hard."

It's 10:30. Shelleman, who came to work at 7 from his Arlington home, breaks for lunch. He doesn't eat breakfast, because after getting off work he eats a big dinner, usually at home with his wife. After riveting his senses to a radar for a few hours, he finds that he likes to get out and "people-watch." So he descends through the busy, peopled airport to an employee's cafeteria on the ground floor.

Up in the tower after lunch, Shelleman puts on his headset and begins to deal with a line of jets waiting to get into the sky. "Eastern 375 clear to takeoff." "This is Eastern 375; can you give me a wind check?"

"Wind check, one seven zero at zero eight."

Eastern 375 says, "Roger", and begins his surge down the runway.

Outside the August day is dense. "They move slow on these hot days, heavy air." Somewhere out in that heavy air, aiming at Runway 18 hard by the Potomac River, is National 471, Northwest 322, and a speck of a private plane who calls himself One Zero Two Tango Whiskey. Eastern 375 rumbles by and lifts for the sky.

On an average day in 1978 this airport saw 965 landings or takeoffs. It was the eleventh busiest airport in the country. "Acre for acre," though, Shelleman thinks it might be the busiest.

National has one "long" runway, measuring 6,870 feet. It is interesected by two shorter runways. Dulles has three runways which do not interesect, and each measures more than 10,000 feet. On the average day in 1978 Dulles handled 365 flights. "But," notes Shelleman, "this (National) is where the money is. People want to use this airport." Some of these people might be called congressmen, who have a parking lot next to the terminal.

In addition to the airport being a comparative postage stamp, some pilots would just as soon avoid it because noise control regulations bind them to the river's course on takeoffs and landings. "That can get pretty hairy," says Shelleman. Further cutting into the airspace is a prohibition of air traffic over downtown -- for security reasons. There is a telephone in the tower. Pick it up and the Secret Service answers.

Jets whine in and out, using the long runway. Around and between them Shelleman weaves smaller, slower planes on the crossing runways. His art is timing, his medium high technology. After awhile, he takes a break, rotating jobs with the other five men in the tower who have been handling other duties such as final clearance and ground control. To bring himself down, he takes the sedate task of extracting a list of future flights from a computer.

Air controllers at busy airports such as National are GS-14s. They start at $32,442 a year and work a 40-hour week. Shelleman thinks he is under paid. "Airline pilots fly a maximum of 80 hours a month. Some of them make $80,000 a year. I think we have as much responsibility as they do."

Out the window there is supporting evidence. Jets keep rolling down the tarmac, and others keep dropping out of the haze. Baggage carts slalom around fuel trucks. People file into a jet; from the tower they look like ants.

"Our safety record is good here." In his 20 years as a controller Shelleman has never seen a bad accident, nor does he expect to see one. But he also admits, "I don't know how I'd respond.

"This job is hard on your nervous system. It should be a little, though." The computer stops chattering for a moment -- a moment to reflect. Shelleman points to a blip on a scope. "Now I see that as one unit. I know what's behind each of those -- people and a plane. But you sit around and think about that too much, and you'll start losing your sanity."