Here's a novel and possibly far-out idea for preventing future disasters at National Airport: Install arresting cables or nets at both ends of the main runway so the pilot could abort takeoffs in emergencies.

Rep. Stanford E. Parris (R-Va.) has embodied the idea in legislation he introduced yesterday in Congress.

The bill would require the Federal Aviation Administration, which owns and operates National, to study the feasibility of installing arresting gear.

If feasible, the gear would be installed by December.

During a news conference, Parris referred to the Air Florida crash on Jan. 13 that claimed 78 lives, including those of four motorists on the 14th Street bridge, which the plane struck seconds after leaving National.

Parris, who plans to run for reelection from a district that includes Alexandria and the adjacent part of Fairfax County, said there are two types of systems that could be used.

One, he said, is "a pop-up cable system that is recessed into the runway. The second is a large net that lies across the end of the runway and upon activation is capable of stopping . . . aircraft. . . with little discomfort for the passengers."

The net system is in operation at some airports used by both military and commercial aircraft, but never has been activated to halt a commercial plane.

The net idea would cost $10 million, Parris said, much of it for runway extensions needed to provide space for the net installation.

Parris pledged to work to transfer much of National's traffic to Dulles International Airport.