Dulles International Airport has won back some airline service, thanks in part to incentives being offered the airlines by the Department of Transportation.

Air Florida, which started its Washington services at Dulles two years ago and then moved all its flights to Washington's National Airport, now plans to resume daily jet service between Dulles and Miami on Dec. 18. It also will continue to operate its four daily flights to south Florida from National.

Air Florida is the first airline to announce some new service at Dulles since DOT Secretary Neil Goldschmidt announced that landing fees and mobil lounge charges would be waived, at least for the next two years, in an attempt to give the airlines some economic incentive to transfer some flights from the more popular, crowded close-in National to the increasingly underutilized Dulles.

Although Air Florida was known to be considering a move to Dulles even before DOT offered the incentives, C. Edward Acker, chairman of the board of Air Florida, said the decision to use Dulles was greatly influenced by DOT's new policy to attract carriers to it.

More airlines wishing to expand air service to Washington may also find Dulles attractive in the future because of increasing pressures on National. Takeoffs and landings already are limited at National, and the numbers are scheduled to be reduced even further next April if DOT's plan proceeds -- a plan currently being challenged by some airlines in court.

In its efforts to make Dulles more attractive, DOT dropped the landing fees, which range up to $220 a landing, and mobile lounge charges, which cost the airlines $55 each time they are used, and it also announced that it would work to upgrade transportation to and from the airport.

Air Florida will resume its Dulles service with a Boeing 737 on Dec. 18 but after Dec. 23 will use a 380-passenger McDonnell Douglas DC10 on flights running Mondays through Thursdays. The aircraft to be used is the one Air Florida uses on its weekend flights to Europe from Miami.

The airline offers all its seats at one unrestricted fare; now $99 one-way, it will go up to $109 on Dec. 15. In comparison, the lowest available fares on most of the other airlines' flights to Miami range from about $250 too $300 with a seven-day advance purchase and often other requirements.

In another airline development, Midway Airlines announced that it is maintaining its current fare levels despite a 6 percent fare increase that will be put into effect by almost all other major airlines, except by Delta Airlines, which also is holding its fares stable. Midway's regular unrestricted fare to Chicago is $107.