IF EVER THERE were a time to get a regional act together and gain long-sought local authority over Dulles and National airports, this is it. But after five months of interjurisdictional squabbling, a 15-member commission appointed by Transportation Secretary Elizabeth Hanford Dole can't even agree on the shape of any future authority to take over the two airports from the federal government. Without some agreement this month, the governments of the District, Maryland and Virginia may forfeit the timely and critical support of Mrs. Dole and key members of Congress.

There are ways to break this impasse. At issue is how many members each jurisdiction should have on a planned regional airport authority. Virginia members want representatives of their state to dominate, citing their immediate and primary interests of noise, surrounding real estate, policing, access and, most important, the need for Virginia General Assembly approval. The Maryland and District members argue that they deserve equal representation on any board that not only would control two airports but would also make decisions that could affect Baltimore-Washington International.

Given the eventual involvement of the Virginia General Assembly, an initial proposal of three members for each jurisdiction might as well be scrapped. But what if Virginia were to have, say, five members, and Maryland and the District five between them? In addition, there could be another member -- an "independent," agreed upon by all three jurisdictions -- who would vote only in case of a 5-to-5 tie.

Whatever the shape of the table and the configuration of the players, the point is to seize the initiative afforded by Mrs. Dole. Governors Robb and Hughes and Mayor Barry should step in personally, along with the members of Congress from the region, and reach an understanding that will deliver the airports to the region. Without it, efforts to achieve balanced airport traffic, convenient service and an understanding with Congress on the allocation and volume of flights will fail, as they always have. The authority over National and Dulles shouldn't belong to any one jurisdiction, but to all three, whose mutual concerns can be protected and strengthened as well.