The Citizens Association of Georgetown, citing potential "apprehension and alarm" among residents, is up in arms against a proposal to route some airplanes landing at National Airport farther from Rosslyn's high rises and closer to Georgetown.

In a letter to the National Transportation Safety Board, which this spring called for the change as a safety move, association Acting President William A. Cochran said it would "aggravate most severely the already very heavy and extremely objectionable noise from aircraft" to which Georgetown residents are exposed.

"Intensification of this problem will generate apprehension and alarm among the Georgetown public in addition to compounding the discomforts and inconveniences suffered for nearly 20 years," Cochran said in his July 25 letter.

Cochran also suggested the shift might compromise safety. "In the last few years the section of Georgetown near the river has become developed with new apartment and office buildings . . . the prospect of an aircraft disaster over or in Georgetown is an ever present thought in the minds of residents."

A safety board official suggested yesterday that the association is overreacting. The board, he said, has proposed shifting an instrument flight path that is used by a relatively small number of planes landing at National. The proposed shift would place them on another path closer to Georgetown that is already used by most planes making instrument landings, he said.

In any case, the Federal Aviation Administration, which determines flight paths, has rejected the safety board's proposal as unnecessary. The board, however, continues to campaign for its adoption.

The proposal grew out of the board's investigation of an incident in which a Piedmont Airlines 737 jetliner apparently passed unusually close to the USA Today building in Rosslyn while making an instrument approach to National Airport last December.

After an examination of landing procedures at National from the north, the board proposed that one approach path that takes planes along a 147-degree heading directly over Rosslyn be shifted to route them more over the Potomac River at Rosslyn.

Many planes already use this 153-degree approach. The crew of the Piedmont jet, in fact, told investigators that they were using that flight path. Investigators found, however, that the plane had apparently diverged from the correct path.