under Leesburg observation and control. It remained under that control either until its journey was complete or it passed out of the area. Aircraft coming into the area were handed over from other control centers, of which there were twenty across the continental United States. The Leesburg center was among the nation's busiest. It included the southern end of the "northeast corridor" which daily accommodated the world's heaviest concentration of air traffic.
Oddly, Leesburg was distant from any airport, and forty miles from Washington, D.C., from which the Air Route Center took its name. The center itself was in Virginia countryside---a cluster of low, modem buildings with a parking lot---and was surrounded on three sides by rolling farmland. Nearby was a small stream named Bull Run---its fame enshrined forever by two battles of the Civil War. Keith Bakersfeld had once gone to Bull Run after duty, reflecting on the strange and diametric contrast between Leesburg's past and present.
This morning, despite awareness of the summer's day outside, everything in the spacious, cathedral-like main control room was operating as usual. The entire control area---larger than a football field---was, as always, dimly lighted to allow proper viewing of the several dozen radar screens, arranged in tiers and rows under overhanging canopies. The control room noise level was what any newcomer noticed first. From a flight data area, with great banks of computers, assorted electronic gear and automatic teletypes, arose the continuous whir and chatter of machinery. Nearby, from dozens of positions where controllers sat, directing aerial traffic, came a ceaseless hum of voice radio exchanges on a host of frequencies. The machinery and human voices merged, producing a constant noise level which was all-pervading, yet strangely muted by acoustic, sound-absorbent walls and ceilings.
Above the working level of the control room was an observation bridge, running the room's full width, where occasional visitors were brought to watch proceedings below. The control room activity looked, from this eyrie, not unlike that of a stock exchange. Controllers rarely glanced up at the bridge, being trained to ignore anything which might diminish concentration on their work, and since only a few especially privileged visitors ever made it to the control room floor, controllers and outsiders rarely met. Thus the work was not only high pressure, but also monastic---the last condition added to by the total absence of women.
In an annex to the control room Keith slipped off his jacket, and came in wearing the crisp white shirt which was like a uniform for air traffic controllers. No one knew why controllers wore white shirts on duty; there was no rule about it, but most of them did. As he passed other control positions while heading for his own, a few colleagues wished him a friendly "good morning," and that was unusual too. Normally, the immediate sense of pressure on entering the control area made it customary to give a hurried nod or a brief "Hi!"---sometimes not even that.
The control sector which Keith regularly worked comprised a segment of the Pittsburgh-Baltimore area. The sector was monitored by a team of three. Keith was radar contioller, his job to maintain contact with aircraft and to issue radio instructions. Two assistant controllers handled flight data and airport communications; a supervisor coordinated activities of the other three. Today, in addition, the team had a trainee controller whom Keith had been instructing, at intervals, over the past several weeks.
Others of the team were drifting in at the same time as Keith Bakersfeld, taking position behind the men they were to relieve, and allowing a few minutes while they absorbed the "picture" in their minds. All through the big control room, at other positions, the same thing was happening.
Standing at his own sector, behind the radar controller about to go off duty, Keith already felt his mental acuity sharpen, his speed of thinking consciously accelerate. For the next eight hours, except for two brief work breaks, his brain must continue to operate that way.
Traffic, he observed, was averagely busy for the time of day, taking into account the widespread good weather. On the scope's dark surface, some fifteen pinpoints of bright green light---or "targets," as radarmen called them---indicated aircraft in the air. Allegheny had a Convair 440 at eight thousand feet, approaching Pittsburgh. Behind the Allegheny Right, at varying altitudes, was a National DC-8, an American Airlines 727, two private aircraft---a Lear jet and a Fairchild F-27---and another National, this time a prop-jet Electra. Several other flights, Keith noted, were due to come on