The Federal Aviation Administration established a communications procedure in 1978 to notify the Soviet Union if an airliner flying the North Pacific was hijacked and considered likely to enter Soviet airspace, according to court records involving the Soviet shoot-down of Korean Air Lines Flight 007 in 1983.

The FAA procedure is outlined in an exhibit to a motion that seeks a default judgment against the Soviet Union, one of the defendants in the complex civil lawsuits brought in U.S. District Court here on behalf of relatives of some of the 269 passengers and crew who were killed.

The FAA document shows, according to the motion by attorney Donald W. Madole, "that specific arrangements for communication with the U.S.S.R. exist in anticipation of unusual aviation incidents."

The document orders FAA controllers in Anchorage to notify controllers in Tokyo "if there are indications that the hijacked aircraft will enter U.S.S.R. airspace." Tokyo controllers, through a communications link in Sapporo, Japan, would contact the Soviets in Moscow by teletype or in Khaborovsk by radio, the order says.

There is no way for the FAA to have initiated a warning, however, if it did not know that the plane was off course. Most of the North Pacific route is far beyond reach of civilian radar monitoring and the FAA has said from the beginning that it had no knowledge of a problem involving the plane.

While there is no question that the Soviets shot down the airliner after it strayed into Soviet airspace, there has been considerable debate about whether U.S. military or intelligence sources were aware that the airliner was off course and thus should have warned the crew through the FAA.

The State Department has said several times, and repeated yesterday through a spokesman, that "it is our position we did not know until after the shoot-down that the plane was off course."

In a U.N. Security Council debate two days after the incident, acting U.S. representative Charles M. Lichenstein departed from his prepared remarks "to comment on the suspicion that the Soviet representative expressed that the United States services followed the flight in the most attentive manner. No, I would assure the representative of the Soviet Union: we followed you following the flight."

Asked about that on Friday, a U.S. official said, "We have never explained that because it gets into intelligence information . . . The obvious implication is that we have information indicating what the Soviets saw." However, the official said in repeating an earlier U.S. statement, the information was developed after the shoot down, not while the plane was flying.

Madole's motion was filed on the order of U.S. District Court Judge Aubrey E. Robinson Jr. because the Soviets have not responded to civil complaints. In addition to the Soviets, the suits name as defendants the U.S. government, Korean Air Lines and Litton Industries, which manufactured the jetliner's navigational equipment. A finding of default against the Soviets, the motion says, does not limit claims against other defendants.

As a practical matter, a default judgment against the Soviet Union would be worthless unless the plaintiffs can find some way to collect, but it would provide a basis for claims to be filed.

The Soviets have charged that the plane was engaged in intelligence activities, which the United States has strongly denied.