Local pressure to curtail night operations at Washington National Airport is given a minimal chance of success because of congressional sentiment and the current Federal Air Regulations governing aircraft sound limits.

The Washington Metropolitan Council of Governments last week called on the Metropolitan Washington Airports Authority to eliminate all flight operations after 10 p.m. and to curtail slots for flights between 8 p.m. and 10 p.m. to reduce the impact of aircraft noise on surrounding neighborhoods.Citizens for the Abatement of Airport Noise, which has charged the

airports authority with being unresponsive to residents' feelings, embraced the Council of Government's suggestion.

But according to Capitol Hill sources, Transportation Department officials and the airports authority, the law authorizing the transfer of National and Dulles International airports to the airports authority restricts its ability to reduce the number of flights and passengers using Washington National.

Currently, large air carriers can schedule a total of 37 operations an hour for the period between 7 a.m. and 9:59 p.m. and commuter and regional carriers can schedule up to 13 operations an hour.

Currently, nine to 10 unscheduled flights, primarily passenger flights, occur between 10 p.m. and 7 a.m., according to authority spokesman David Hess.

Any attempt at curtailing the 7 a.m. to 9:59 p.m. flights would run counter to the transfer law that locked in air carriers' access to 37 hourly slots and the 13 slots for commuter and regional airlines.

The 9:59 p.m. cutoff of the 37 hourly slots effectively forces airlines to use only their quietest jets in order to avoid a curfew.

But even though National is open 24 hours a day to aircraft which meet the noise rules, as a matter of course the airlines don't schedule any late night flights, said Mr. Hess.

Airline officials explained that the few flights that do arrive after 10 p.m. often have been delayed because of weather or mechanical problems, and only land at National if the jet meets stringent sound level limits established by the Federal Aviation Administration.

An absolute ban on landing after 10 p.m. would force such delayed flights to land elsewhere.

Additionally, the transfer law that Congress passed in 1986 lifted the previously enforced annual passenger ceiling of about 14.6 million passengers and, as a result, National is growing.

The Council of Government's recommendations were received by the airports authority as part of a Federal Air Regulation Part 150 noise study required by FAA regulations.

The airports authority is conducting two Part 150 studies, one concerning Washington National Airport, the other concerning Dulles.

We expect those studies to be out sometime this summer, Mr. Hess added.

A congressional staffer involved in guiding the passage of the transfer bill said that lawmakers will watch closely for any signs that the authority might move to restrict use of both airports.

Reducing noise impact is an important goal but one that can and should be achieved without cutting back the airports' use, he added.