A lawsuit filed on behalf of a woman who, along with a Fairfax County elementary school principal, was killed in a car crash last year in McLean was settled out of court yesterday for $390,000.

Lawyer Edward M. Holland, who represented relatives of Agnes H. Gaskins, 48, the principal's secretary at Cunningham Park Elementary School in Vienna, said the settlement was negotiated as the trial was beginning in Fairfax County Circuit Court.

"We had empaneled the jury, we were ready to go," said Holland. "The whole family was distraught to have to relive the accident again."

Holland said it was the final settlement of three lawsuits filed in the June 12, 1984, crash. Neither Holland nor the attorneys who handled those lawsuits -- one filed on behalf of the principal, the other by a passenger -- would comment on the other settlements.

Gaskins, who was driving the car, and Principal Dumont J. Walker Jr., 44, were killed when a tow truck traveling north on Balls Hill Road near McLean swerved into the southbound lane and collided head-on with the Cadillac in which they were riding, Fairfax County police said. Mattie Lambert, 43, another passenger in the car, was injured.

The driver of the tow truck, Christopher Gill, who was employed by Hams Crane Service, was not injured.

The lawsuit filed on behalf of Walker claimed that Gill was negligent in failing to keep a proper lookout, failing to drive on the right side of the highway, failing to pay full time and attention and failing to operate the truck at an appropriate speed. It also named Hams Crane Service as a defendant.

The suit also claimed that a van-type motor vehicle, owned by Media General Cable of Fairfax County Inc., another defendant in the suit, was parked on the surface of Balls Hill Road for nonemergency reasons obstructing traffic and contributing to the accident. The driver of the van, Ronald E. North, also was named in the suit. The lawsuits filed on behalf of Gaskins and Lambert were not available.

Brian H. Rhatigan, an attorney for Media General, said the settlement was "no admission of liability" and would not comment further on the lawsuit.

Richard H. Lewis, an attorney for Hams Crane Service, also would not comment on the settlement.