IT WOULD TAKE too much red carpet to do the whole access road out to Dulles International Airport, but a first-class welcome is in order for Pan American World Airways' decision to land big at Dulles. By establishing the first hub there -- quadrupling its number of weekly flights from 14 to 56 and adding perhaps 10,500 new passengers a week -- Pan Am should make the going great at an airport that couldn't be more ready for a break.

If officials at Dulles have toted it correctly, the move could inject an additional $100 million more a year into the local economy: spending for hotels, restaurants, fuel, rental cars and other services. Better still, Pan Am's decision puts the "I" for International in DIA in a serious way, with the terminal becoming a connecting point between Mexican and South American flights and those on the airline's European network.

Aside from what this will do for the region and for the airport, it will do good things for air travelers: new nonstop service to Frankfurt and Mexico City, plus four weekly flights to Paris and three weekly to Rome. Also, there will be daily nonstop flights to Miami, Orlando and Tampa/St.Petersburg. All of this is effective June 1, with more to come later, according to Pan Am.

Other airlines are finding things to like at Dulles too. New York Air started service from Dulles in February, and now offers about a dozen flights; it also is building facilities that will allow passengers to skip the mobile-lounge game and instead get on and off planes directly. Eastern has added four daily round trips between Dulles and New York, and Presidential Airlines plans to start serving Dulles and five other cities between Jacksonville and Boston.

With still other feeder-line service a likelihood, the prospects are good for a better balance of air traffic between Dulles, Baltimore-Washington International and National airports. All that is needed to top it off is agreement in Congress on Transportation Secretary Elizabeth Dole's proposal to get the federal government out of the airport-ownership business at Dulles and National. A regional authority can do this job -- and make all three airports the better for it.