Officials at Dulles International Airport, frustrated in their attempts to keep deer off the runways, plan to install an electric fence that could cost as much as $42,000.

According to officials, nine deer have been killed by commercial aircraft taking off or landing since April 1985. The most recent accident involved a DC-9 in April.

No major damage to large aircraft has been reported in any of the accidents, officials said, and no one has been reported injured. Damage to smaller aircraft involved in such accidents has been more extensive, officials said. In all instances the deer were killed.

Although several accident reports involving deer listed the kind of aircraft as "unknown," one involved two deer and a DC-9, two involved a Boeing 767 and one a Boeing 727.

Airport managers' efforts to prevent such accidents have included a controlled hunt every fall since 1972. Last year, 300 deer were "harvested," airport manager Dexter Davis said. The hunts are conducted by airport police, he said.

The fence will be six feet high and will have five electrified wire strands that will shock the deer if they graze too close to it, Davis said. It will not kill or injure them.

Construction bids went out recently, and officials hope the fence will be installed before the fall mating season, when deer are bolder and more likely to wander on to the runways.

Hundreds of the animals roam the 10,000 acres that make up Dulles airport, Whittle said, and they feel safe because "the public can't hunt them, there are no predators or automobiles and there is no problem with food."

The problem is typical in rural areas, Davis said. Metropolitan Washington Airports Authority officials talked to managers of several airports in rural areas that were having similar problems. One of the suggestions was to put up an electric fence, said David Hess, airports authority public relations director.