A federal appeals court has found that the Department of Transportation exercised its authority properly when it temporarily allocated access to Washington's National Airport last fall when the airlines were unable to do it themselves.

In a unanimous decision, a three-member panel of the Eighth Circuit Court of Appeals in St. Louis disagreed generally with all the arguments advanced by Northwest Airlines and five other airlines that intervened in an attempt to overturn the DOT's allocation plan. A different appeals panel had turned down the carriers' request for a stay of the plan pending review of DOT's action on the merits.

The plan, which distributed takeoff and landing privileges after Dec. 1, required several airlines to give up some flights and a total of a dozen airlines to move some flights to the less desirable 10 p.m. hour. Also under the plan, New York Air was able to begin its low-fare service between Washington and New York, and several other airlines new to National were able to expand their services.

With antitrust immunity, the airlines had been working out operating schedules at the airport among themselves since 1968 with the government's blessing. Last fall, however, because too many airlines wanted too many operations at the restricted airport, they were unable to come up with their own formula and notified the government of their failure. The DOT emergency plan, however, obviously displeased some of the airlines whose planned operations were altered.

Northwest had argued that the DOT secretary had no statutory authority to allocate slots -- the industry term for takeoffs and landings -- among airlines, that the method by which it was done was "arbitrary and capricious" and not the product of "reasoned decision making," and that the secretary did not comply with certain procedural requirements before issuing the regulation that distributed the slots.