By MEG JONES

Oshkosh - Paratroopers jumped out of them, gliders were towed behind them, Jeeps and other cargo were hauled in them and their first paying passengers dressed up to travel in them.

Seventy-five years old and still flying, the DC-3 and its military counterpart, the Army Air Force C-47 and Navy R4-D, were so critical to aviation history, historians contend, that without them World War II might have ended differently for the allies and commercial air travel would not have taken off as quickly as it did.

The venerable DC-3 is being feted this week at EAA AirVenture, where about three dozen of the planes in both commercial and military designation are flying in formation and parked in static displays to celebrate its birthday. On Monday afternoon, 21DC-3s and C-47s flew in formation over Oshkosh. More than 16,000 were built by the end of World War II, and hundreds are still in use.

"This was the first plane that made commercial airline travel possible," said John Tegtmeier, a retired American Airlines pilot who is in Oshkosh with the Flagship Detroit Foundation. "Before then they had to rely on air mail contracts to make money."

DC-3s could carry 21 passengers - seven more than the DC-2 - and airlines could finally make a profit flying humans instead of just cargo and mail. Still, in the late '30s when the Flagship Detroit was flying, a Dallas-New York plane ticket cost $260, which meant only the rich could travel by air. This week AirVenture visitors can walk through the Flagship Detroit for $3.

In the '30s American Airlines named all its 82 DC-3s after cities and states, and the foundation has painstakingly restored the Flagship Detroit, which flew with American Airlines from 1937 to 1947 and was the 45th plane to roll off the DC-3 assembly line in Santa Monica, Calif.