Top officials of 30 airlines apparently got what they wanted yesterday in a two-hour meeting with Transportation Secretary Drew Lewis and Federal Aviation Administrator J. Lynn Helms. They were assured that the air traffic system is safe and that they can rely on the reduced schedules they are operating.

"We are flying more seats than we are passengers right now, and part of it, we believe, is the uncertainty with respect to the schedules," Paul R. Ignatius, president of the Air Transport Association, told reporters at a briefing after the meeting, called as 12,000 members of the Professional Air Traffic Controllers Organization were spending their ninth day off the job.

The airline officials were told they can consider their current schedules as set through Labor Day. They will be told in two weeks how many flights they will be able to operate from Labor Day through at least the first of the year, possibly through next Easter.

The post-Labor Day schedule, however, is not likely to be a return to normality. "We're probably going to be operating -- although we hope it's not the case -- at the 75 percent capacity, possibly through April 1, until we have enough people trained to start upgrading the system," Lewis said. "Our first obligation is safety."

The current FAA plan, called the "50 percent flow" plan, has adjusted flight activity at each airport to a level considered consistent with the available personnel when the controllers' strike began. It required that each of 22 major airports begin operating at 50 percent of its normal air traffic control capacity.

The FAA plan allowed the major airports to operate extra flights if they could be accommodated safely. Because of the number of airports that didn't have to make such reductions, the plan has resulted in a 75 percent flight schedule level overall.

The airlines individually selected the flights they would cancel. Each of the airlines operating at the 22 restricted airports were told hour-by-hour what percentage of normal arrivals the airport could accommodate -- 30 percent of normal traffic between 9 and 10 a.m., for example, or 50 percent between 11 a.m. and noon.

Thus, a carrier with 10 flights arriving within an hour that could accommodate only 40 percent of normal traffic had to cut six flights.

"Each carrier had to go through that exercise," explained Neal Meehan, president of New York Air. Because NYA operates at New York's LaGuardia Airport, one of the nation's busiest, its schedules were cut more than some airlines; it is operating 68 percent of its normal LaGuardia flight schedule.

Because the airlines operate out of different airports on very different route structures, the impact of the reduced flight schedules varies considerably.

Except for its international flights, Air Florida is operating about 99 percent of its schedule, C. Edward Acker, its chairman, said yesterday. "Up to this point, we haven't been required to cut anything," he said. "We didn't have a great number of flights within the given hours to be cut."

Airlines cutting flights tried to cut the flights that had the fewest passengers booked in the next few weeks, as well as flights to cities where other carriers had more extensive service, officials said.

"We're alive and well," said Jerry Gitner, president of People Express, a new airline that started service in April. Under its normal schedule, People Express operated five or six flights a day to each city served. Where it had six flights a day, it now has five, Gitner said.

By all accounts, the airline officials meeting with the government yesterday didn't complain at all about the inconvenience or losses in revenues they are suffering as a result of the strike and the plan. "What we must do now is to adjust to the reality of the situation," the ATA's Ignatius said.

With the promise of schedule stability, "the second thing we need is customers," John J. Casey, chairman of Braniff International, said. "And they will come if they can be assured that they can fly where they want to fly."