Republic 325: promptly cross 30 Left. Eastern 272: hold short of 30 Right.'' It is the early evening rush hour at St. Louis's Lambert Field. In the glass-walled control tower, which some here call ''the penthouse,'' air traffic control trainee John Joseph watches from the window as he issues taxiing directions in clipped verbal shorthand to pilots of planes moving to or from the runways. A senior controller at his elbow listens and occasionally intercedes.
Mr. Joseph, hailed as a ''super young talent'' by one of his supervisers, is one of the new breed of air traffic controllers who are slowly beginning to fill the massive void left when 11,400 members of the Professional Air Traffic Controllers Organization were fired after an illegal strike in August 1981. The job is a vital one. With the help of computer, radio, and radar, these Federal Aviation Administration (FAA) workers guide 85,000 flights a day.
Tonight, two other trainees in the tower, also watched and coached by senior controllers, issue other orders over their headsets on varied frequencies in similar rapid-fire fashion. Though soft music plays in the background, the level of concentration here is high and the atmosphere businesslike.
Joseph, whose delivery speed rivals that of the nonstop ''Trouble'' song about River City in ''The Music Man,'' was a University of Missouri junior in engineering when he saw a newspaper ad over a year ago announcing a civil service exam for those interested in air traffic control. He was later invited to enroll in the FAA's training academy in Oklahoma City. He was one of 10 in a class of 19 to pass. He has been at Lambert for the last eight months.
So far, Joseph has checked out in two of the basic tower jobs and looks forward to mastering the others here and in the radar room below. As one who held two full-time jobs while a college student - he tended a shoe warehouse afternoons and worked nights cleaning up at a movie theater - he is clearly interested in moving ahead as fast as he can and reaping the salary gains.
''Standing still, you're not doing anything - I've got to keep myself moving, '' he explains. Though he had planned to get married, he now feels he should wait until his job is more secure. ''I could be let go at any time.''
The FAA insisted from the day of the firing that, by leaning more on computers, it could do the job with about 3,000 fewer controllers than its one-time force of 16,000. Most of the military controllers and about half of the FAA supervisors who filled in during the emergency have gone back to their old jobs. And the FAA's Oklahoma academy, which initially tripled its enrollment on a double shift, is back to one shift and recruiting for attrition only.
Still, the job of rebuilding the nation's intricate air traffic system has been an extraordinarily difficult one. And the test of its effectiveness is yet to come.
Many veteran controllers who stayed on at busier airports after the strike have had to work six-day weeks with reduced vacations. They are spending increasingly large chunks of their time helping to train others, a job many of them do not relish.
Though plane traffic was initially cut back by about one-third, flight schedules are now close to normal at most airports. Some, such as Lambert Field, are handling even more traffic. Touchdowns and landings here, averaging 90 an hour, are up 117 percent since just before the strike.
''We were devastated by the strike - we lost 41 of our 54 air traffic controllers,'' recalls Thomas R. Davidson, an FAA assistant manager who watches over operations in both the control tower and the radar room at Lambert.
''We used to draw people from other facilities with three to five years' experience. But this forced us to take people off the street with . . . no experience. It really taxed our imagination and our abilities. But it wasn't a multiple-choice situation. We faced a hurdle and we had to jump it.''
Under a new national FAA staffing arrangement, controllers no longer spend four to five years mastering the total job, but train for and check out in each of 12 or 13 different positions. FAA spokesman Dennis Feldman says the change allows trainees to become ''immediately productive.''
''We've learned to work smarter, not harder,'' says Lambert's Mr. Davidson. In addition to creating a new controller position to coordinate plane backups from the gates, the St. Louis airport has also redesigned its air space several times recently to move traffic more efficiently, he says.
What kind of a person makes a good controller?
''You need a sense of humor as a release valve,'' says Davidson. ''It takes someone with a willingness to accept criticism and an eagerness to progress against bountiful odds. It takes years to become a professional in this job and the frustration level is very high. You have to be a good communicator, and your listening skills have to be very active.''
Though he takes his job seriously, John Joseph says he does not feel overwhelmed by the pressures of it - partly because several other controllers would also have to miss something for any mishap to occur.
''I used to think, 'I'm in charge of 100,000 lives.' I do feel responsible for the airplanes, but I don't worry about it. The FAA gives you lots of psychological tests because they want to be sure you aren't going to panic.''
Like all trainees, he knows that brevity and clarity are critical. ''You have to be decisive and able to get across what you want done. I get long-winded sometimes. They pick on me because they say I tell them (pilots) too much.''
''You have to speak clearly and not too fast or you just end up repeating yourself,'' confirms Jennifer Berlin, another Lambert trainee.
Veteran Lambert controller Jerry Styczynski agrees with other controllers that the particular zest of the job comes with the intensity of the action. And for him, selling automobiles would be far more stressful, he says.
''After a day in the tower, I go home just exhausted - but it's exhilarating, and I thrive on it,'' he says. ''What we don't like here in the tower is that there are two or three trainees now working at once.''
''It's like anything else - but you can't become complacent in this business, '' says Jack Lee, who works chiefly in Lambert's radar room and has been at this airport 26 years. ''You find out very rapidly that you're dealing with other human beings and not just airplanes.''
As most controllers tell it, the key part of their job is making sure that plane traffic is properly separated in every direction. ''It's like playing three-dimensional chess on a one-dimensional chess board,'' says Davidson.
Joseph admits he harbors a profound respect for many of Lambert's longtime professionals and the breadth of their experience.
''Some don't do traffic as rapidly as I do, but being faster doesn't necessarily help if you get in trouble,'' he says. ''They can always dig themselves out of a hole and do it safely and correctly because they know the total picture. . . . I'm really impressed with them.''
It is that breadth of knowledge and the ability to understand other people's problems which some critics cite as a major drawback in the new FAA training strategy. ''The FAA is trying to push people through too fast,'' says former Chicago controller Roy Bozych. ''They need more seasoning.''
But the National Transportation Safety Board, which has been keeping close tabs on the controller rebuilding process from a safety standpoint, has been far more concerned that the FAA find new and effective ways to cope with controller fatigue and stress and to improve worker-management relations which were a major factor in the strike. The board has also been urging the FAA to limit plane traffic until all supervisors are back at their original jobs.