Federal officials are giving serious thought to letting more propeller-driven, low-noise commuter airplanes use National Airport, according to aviation sources.
Under current rules, 11 commuter flights an hour are allowed at the airport. Aviation sources said the Federal Aviation Administration may raise that by a small, unspecified number.
The rise, if approved, would apply only to planes that could land and take off on National's two shorter runways without crossing the main runway, sources said. That way, they would not interfere with jet traffic on the longer runway.
Most such flights would be made by DASH-7s, modern, short-haul turboprop planes operated by Ransome Airlines and Hinson Airways, the two largest commuter airlines at the airport.
The four-engine planes seat about 50 people and are among the quietest passenger planes flying. They are quiet enough to meet noise standards that close National to jets after 10:30 p.m.
Commuter airlines have long campaigned for more access on the grounds their planes are quiet and would place little extra load on the airport's facilities. Civic groups, while not happy about the prospects of more planes of any kind at National, prefer commuter planes to jets.
The change is being considered as part of a review of a traffic and noise policy implemented at National in 1981. Federal officials are also reported to favor reducing the number of passengers allowed to use the airport from the current 16 million to about 15 million.
A U.S. Department of Transportation spokesman confirmed that the overall traffic and noise policy is under review but said senior officials have made no decision on any changes.