The Federal Aviation Administration has rejected recommendations that planes making instrument approaches to National Airport be routed further away from high-rise buildings in Rosslyn. The FAA said the current paths are safe.

The agency's statement, released yesterday, came in response to recommendations issued last March by the National Transportation Safety Board, which said a Piedmont Airlines 737 jet in December probably passed too close to the USA TODAY building on Wilson Boulevard.

"The presence of large buildings . . . is not unique to Washington National Airport," said a July 5 letter to the safety board from FAA chief J. Lynn Helms. "When properly flown, the approaches to Washington National Airport present no unusual risks along the approach path and provide more than adequate margins of safety."

The FAA is conducting a study of planes using the instrument approach from the north to see how often they stray from the required courses and altitudes, Helms said.

The Rosslyn buildings have for years been cited as a safety hazard by groups that favor reducing National traffic. The FAA has maintained they meet safety standards.

The safety board had recommended that one instrument approach path from the north that takes planes over Rosslyn at about 1,100 feet altitude be shifted so that aircraft would be closer to the river.

Helms' letter rejected the suggestion, saying the current route meets safety standards and moving it would not enhance safety.

The board recommended pilots using another instrument approach from the north be required to stay at 720 feet until they are well past Rosslyn. Helms rejected that, saying current systems gave pilots adequate information on the best rate and angle of descent to maintain.

Helms also disapproved proposed amendments to procedures by which pilots shift from instrument flight to visual flight. The changes could increase occurrence of "missed approaches" in which a plane must turn back and try again and cause other technical problems, he said.

Helms also rejected a recommendation to relocate National's radar antennas.