If air traffic controllers go on strike next Monday, about half of the flights across the country will be canceled and most of the others will fly on different schedules, according to the Federal Aviation Administration.
FAA spokesmen were traveling to airports throughout the country earlier this week to warn passengers that the threatened strike would disrupt airline traffic. But they promised that the planes that were allowed to fly would be handled safely by supervisory personnel.
At the same time, the president of the Professional Air Traffic Controllers Organization (PATCO) warned passengers that the FAA plan to keep control towers operating with supervisory personnel would be dangerous.
If most of the controllers walked out next Monday, the FAA says:
* Most flights less than 500 miles would be canceled. FAA officials believe that people would be able to find other transportation for such short trips.
* Most long flights would depart, but probably not on schedule. International flights will get priority.
* Few private planes would be allowed to land at commercial airports. Private planes at general aviation airports would have to land by sight, not by instrument, and would not be allowed to fly higher than 18,000 feet.
* Regular military flights would not be aided by civilian air controllers, but any emergency military flights would have top priority.
* Service to some smaller airports could be completely canceled, especially the first day of the strike.
Air traffic controllers are planning to strike nationwide if their demands for higher wages, shorter hours, and more benefits are not met. The average controller makes about $35,000 a year and PATCO is asking for a $10,000 a year raise and a four-day workweek.
The controllers argue that the job is so mentally taxing that most of them are forced to retire early, when other people are at the peak of their earning potential.
The FAA does not have the authority to grant most of the demands that the controllers seek, an agency spokesman said. Wages and hours are set by Congress. All bill granting what the controllers want is pending before Congress, he said, but the Reagan administration opposes it.The FAA estimated that meeting PATCO's demands would cost the federal government $1.5 billion the first year.
The strike is still uncertain. Air traffic controllers are prohibited from striking under a 1973 injunction. The FAA said that it would consider criminal action against any strikers.
How many of them will defy the injunction and jeopardize their careers is uncertain.
[UPI reports that at least 20 members of the Senate have signed a letter demanding that Robert Poli, president of the controllers union, explain a June 22 strike deadline in view of testimony last year that there would be no strike. ]
[On Aug. 25, Poli told the Senate aviation subcommittee, "In no way is PATCO planning to go on strike in 1981. . . ."
In the letter the senators add: "We want to make clear our position that illegal action will do nothing to further your goals of increased pay and changes in working conditions."]
"The controllers are trying to make everything run as smoothly as possible between now and the 22nd," said one tower supervisor, "so that the public will be able to see the deteriorization when the strike begins. You can see some controllers mumbling to themselves, trying to decide whether they will walk out or not. There's a tremendous amount of peer pressure."
If all the controllers strike, the towers will be operated by supervisory personnel alone. At Tampa International Airport, for example, the 65 air controllers would be replaced by 15 supervisors. They would be able to keep between 45-50 percent of the commercial traffic flying.
The FAA says that the flights would operate with all the normal safety standards, but PATCO disagrees.
Robert Poli, president of PATCO, says that if the strike occurs, he would "warn Americans that it is unsafe to fly." He said that some of the supervisors have not manned traffic control radars for years and others are not medically qualified.
The airlines figure that they would lose as much as $100 million per day if controllers strike. They say some of the weakest airlines could be ruined if the strike lasts lon g.