Only about half of the 11,400 controllers fired by the government have offered their supervisors the oral or written appeals that might allow them to regain their jobs, a Federal Aviation Administration spokesman said yesterday.

Many of those who do appeal say that they attend the sessions not to present their side, but to gather facts to bolster their cases, which they expect to be settled eventually in court.

Fired controllers have a seven-day period to appeal to their supervisors. If they are not rehired, they have 20 days to appeal to the Merit Systems Protection Board.

This week, the FAA sent instructions to the control tower chiefs who can decide whether to rehire the fired controllers, outlining the conditions under which the controllers could return to work. Those who called their towers before the strike to say they feared harassment have the best chance of being rehired, according to the instructions. Those who called after the firings have little chance.

About 130 of the fired controllers nationwide have claimed they were intimidated into staying away from work, the FAA said.

A tape of one of the initial hearings at the FAA facility in Leesburg during the seven-day appeal period reveals a session as stalemated as the prestrike negotiations.

Raymond Steiner, 32, a member of the Leesburg Professional Air Traffic Controllers Organization Local 204, received his notice of intended dismissal on Aug. 10.

After responding with a PATCO form letter requesting an extension of the reply period, Steiner received a mailgram from Angelo E. Viselli, chief of the FAA Washington center, denying his request for an extension and saying "you may call for an appointment to review the material relied upon to support your proposed removal."

His hearing took place a week after he received the letter. Steiner, and Jim Stakem, a PATCO representative, met with Marcus Costello, an assistant sector manager of airway facilities, who was designated as an "Oral Reply Official."

But while Costello was asking why Steiner should be hired, Steiner was asking why he should be fired.

"The purpose of this meeting is for you to make a presentation as to why adverse action should not be taken against you as proposed," Costello said.

"My question is why is this action being taken against me?" Steiner replied.

Instead of presenting a case, Steiner asked a number of questions, including how the government defines "harassment" as regards union activity, and whether the president had fired all striking controllers on Aug. 5. The answers to those questions, Steiner said, were necessary to present his case to the merit board.

Only about 10 of the 180 members of the Leesburg local still on strike have attended the initial hearings, Steiner said. None of them intended to present their cases there, because what they say could be used against them in court, he said.

Since Steiner and the others have gathered information about the charges against them at these hearings, there is really no need for other PATCO members to appeal at this point, said Bob Adams, a spokesman for the union's Leesburg local.

But PATCO officials are urging that all fired controllers take their cases to the merit board, and if necessary, to court, he added.

In response to a question about whether those appealing to their supervisors were simply trying to snarl the government's attempts to handle the walkout, Steiner said, "I'm just trying to protect my rights. But if it makes more paperwork for them, it certainly doesn't break my heart."

Steiner refused at the hearing and in an interview to say whether he had been on strike, because of "the legal ramifications," although he said was on vacation on Aug. 6, the date on which the dismissal notice accused him of striking. In another development, the government said yesterday that it will reject requests for federal aid from fired controllers who miss three mortgage payments and apply to the government for help.

An internal memo from the Department of Housing and Urban Development advised regional offices that if "the mortgagor's default was caused by a loss of employment related to the PATCO action, the application should be rejected."

"Most PATCO members left their jobs voluntarily and illegally," the memo said. "The loss of employment was not beyond their control."

The HUD program is intended to protect homeowners threatened with foreclosure because of temporary circumstances beyond their control. It allows the government to pay off the lender and take over the mortgage for up to three years, while devising with the homeowner a program of reduced, suspended or waived payments.