Renewed push to cope with hazards of winter navigation . . . and DC's National Airport

Conditions at Washington National Airport -- long held by airline pilots as one of the most dangerous in the country -- are bound to come under new scrutiny , say aviation officials.

The impetus: the crash of an Air Florida Boeing 737 in the icy Potomac River Jan. 13, which by this writing had claimed some 76 lives.

Pilots flying in and out of the airport, built on swampland and opened in 1940, face twisting approach and departure corridors and short runways.

Aircraft taking off and landing at the airport are required to follow the curving courses of the Potomac and Anacostia Rivers to ensure that they keep well away from the White House and Washington Monument. Climbing steeply, they are then compelled to throttle back to reduce engine noise over Georgetown and the Virginia suburbs.

When taking off to the north, aircraft must make a hard left turn, passing over the 14th Street Bridge, where several motorists were killed in Wednesday's crash when the Boeing 737 sliced into their vehicles. The bridge links Washington, D.C., with Arlington and Alexandria, Va.

Pilots prefer flying straight into the airport, their attention focused on speed and altitude rather than final approach maneuvers, experts say.

National's three runways have given cause for concern for many years. Only one -- 6,800 feet long -- is considered adequate for safe jet takeoffs. This one , moreover, has no overrun space.

While pilots have serious misgivings about the safety of National Airport, officials caution against speculation that either a short runway or a curving flight corridor caused the accident.

Joseph Stiley, a corporate pilot from Alexandria, Va., who survived the crash , has implied that the Air Florida flight may not have been properly de-iced, with the result that it might have been too heavy and stalled in flight.

Officials of the National Transportation Safety Board (NTSB), which is investigating the crash of Air Florida's Flight 90, have impounded both the de-icing fluid used on the aircraft as well as a sample of the aviation fuel it used. They will be probing to see if the aircraft suffered an instrument or engine malfunction. The Boeing Company says that the twin-engined plane enjoys one of the best safety records. The aircraft, which is currently being flown by 125 operators, is said to be able to operate from short runways. The NTSB will also be examining the possibility that pilot error caused the crash.

A former NTSB official declared some years ago that National Airport ''is so dangerous, it's safe.'' His implication that pilots take particular care flying in and out of the airport is borne out by National's safety record.

Prior to Wednesday's tragedy, the only fatal crash at the airport occurred on Nov. 1, 1949, when a P-38 Lightning, flown by a Bolivian air force officer, collided with an Eastern Airlines DC-4, killing its 51 passengers and crew of four.

National Airport, which was originally designed to handle 6 million passengers a year and now handles 15.1 million, is the 10th busiest airport in the US and the 16th busiest in the world.

Even though the Department of Transportation (DOT) has privately considered closing it, the 710-acre facility survives for one overriding reason: It is convenient to the Capitol.

Travelers -- senators and congressmen in particular -- would rather brave use of National Airport than take an hour to get out to Dulles International Airport in Virginia or to Baltimore-Washington International Airport in Baltimore. Some of the airport's critics say Congress and the courts have frustrated attempts by the DOT and local politicans to restrict growth and muzzle noise at the airport.

The Air Florida crash may lead to further curtailment of fights at National Airport, already cut 21 percent as a result of the air traffic controllers' strike. Regulations that go into effect April 26 at the airport will further reduce flights -- though only slightly -- and set a 16 million ceiling on the number of passengers the airport can handle each year. In addition, airlines using National are currently debating ways of transferring more flights to Dulles, which only handles 2.5 million passengers a year.