When the weekend traffic comes to its usual semi-standstill on I-95 between Woodbridge and Fredericksburg, get smart and get off at Quantico, where you can take a break at the Marine Corps Aviation Museum.

Now in its sixth season, the museum's fairly small but very choice collection is as eclectic as the manifold missions of the corps, including infantry weapons, tanks and aircraft. It's all housed in Quonset-hut hangars that themselves predate the Second World War.

"Everything here is authentic," said Lt. Col. Herman C. Brown, the officer in charge. That means not only the tent representing an operations room in the South Pacific but the helmets serving as basins on the washstand outside it. And it most particularly means the fighter planes, which are flyable.

"Flyable in the sense that they've been restored to flying condition," Col. Brown said, "not that we'd ever fly them again. These aircraft are irreplaceable; some are all but unique." His pet and pride is a Grumman F4F-4 Wildcat, the type flown by Marine pilots until they were gunned into scrap in the gallant last stand at Wake Island.

The museum eventually will be expanded to embrace more aspects of Marine activity, but they're going slow to make sure they get it right. Brown's staff works in front of a tough audience: Many of the visitors are veterans who remember their wars with the clarity of detail that comes from living in the presence of death. The other day, four of them were clustered around a gleaming Hellcat, arguing such esoterica as whether the width of the cowling flaps was correct. They concluded that it was.

MARINE CORPS AVIATION MUSEUM -- At Quantico, Virginia, about 35 miles south of Washington via I-95. Take either Quantico exit; sentries will direct you from the gates. Open April 1 through November 28; hours 10 to 5 Tuesday through Sunday (till 6 on Saturdays), including holidays. Closed Mondays. Information: 703/640-2606.