The Federal Aviation Administration has proposed spending more than $11 million next fiscal year to improve taxiways, buildings, utility systems and other facilities at National Airport.

Airport spokesman Dave Hess said the money, which would include the first major capital funds for buildings in several years, would not increase National's capacity. "I see nothing here that's expansion," Hess said.

The proposal comes as the FAA has adopted a policy of encouraging airlines to transfer service from National to Dulles International Airport, which is underused. The FAA owns and runs both airports.

Civic groups campaigning to reduce traffic at National have opposed major capital improvements there, saying that they would make the busy airport more attractive and slow the shift to Dulles. "We don't want anything more than necessary immediate repairs and improvements," said Joe Doherty, spokesman for the Coalition on Airport Problems.

Doherty and Rep. Frank R. Wolf (R-Va.), the coalition's main ally in Congress, declined to comment on the FAA's proposals until they have studied them.

The proposals, Hess said, are aimed primarily at fixing up aging facilities. The main items:

* $4.3 million to rehabilitate aprons and taxiways, including resurfacing the apron in front of the general aviation terminal and improving ramp lighting.

* $1.6 million to improve airport buildings, reroof hangars and paint interiors.

* $3.8 million to improve utility systems such as steam and water and replace a cooling tower in the north terminal.

* $475,000 to install a new 12-inch water line.

* $1 million to remodel restrooms, improve signs, enlarge an equipment storage building and make other improvements.

The FAA proposes to spend a $4 million more on capital improvements at Dulles. Most of the money would go toward reroofing buildings, improving baggage claim facilities and snow removal equipment and rehabilitating roads on the airport grounds.

Total spending for the two airports would be $15.3 million. For this fiscal year, Congress appropriated $11.1 million for capital improvement at the two, with most of the money going to extend the safety overrun area at the north end of National's main runway.

Last fiscal year, $17 million was appropriated, with construction of a connector road between the Dulles Access Highway and Interstate 66 taking most of the funds.