Piedmont Airlines, the carrier with the Southern accent, is taking a crash course in Bawlamerese.

The fast-growing Winston-Salem, N.C.-based airline unveiled plans today to operate 28 daily flights out of Baltimore-Washington International Airport beginning July 15, establishing the airport as one of the airline's three hubs and making Piedmont the heaviest user of BWI.

Airline officials said the expansion from Piedmont's current schedule of six daily BWI flights would add 170 jobs and likely be the forerunner of a much greater increase in the airline's service out of the airport. BWI is building a $20.9 million gate expansion for Piedmont's use. The 12 new gates will increase the airport's size by nearly 50 percent.

"We intend to be a very, very major portion of the air transportation in the Baltimore-Washington area," Piedmont President William R. Howard said during a press conference at the airport. "We thought BWI was underserved."

Howard said the airline plans to add service to Baltimore on a monthly basis for the next several months as its new terminal facilities near completion, which is scheduled for late fall. He said Piedmont believes the 22-flight increase in service set for July is the largest single increase in service by one airline in a single airport in U.S. aviation history.

Howard would not speculate how many daily flights Piedmont might eventually operate out of BWI, but the airline is running 129 daily out of its Charlotte hub and will expand operations at its recently opened Dayton, Ohio, hub to 38 flights a day from 29 in early July. Howard said BWI "has four times the potential" of Charlotte, based on population.

"It's very clear that beyond July we will add dramatically" to operations at BWI, Howard said. "We will add transportation to the hub until we find there are no more logical spokes to be added to the hub."

Piedmont's expansion at BWI will not affect its operations at National Airport, at which it operates about 25 flights each day. Piedmont officials said the airline is the third-busiest at National.

The 28 flights Piedmont will operate out of BWI each day will make it the airport's largest customer. There are currently 95 flights operated by 25 airlines arriving or departing BWI each day, according to T. James Truby, Maryland Aviation Administrator, with USAir, with about 24 flights, the busiest airline at the airport.

Piedmont has taken advantage of airline deregulation to build hubs in medium-sized cities fed by flights from larger and smaller cities. The strategy has expanded the airline's share of the Charlotte market to 67 percent from 8 percent four years ago. Piedmont estimates that about 50 percent of the passengers using its hubs originate locally, with the rest transferring from other flights, usually Piedmont's.

Piedmont is adding eight new Boeing 737s to its 77-jet fleet to handle the Baltimore expansion, and Howard said that the airline will increase its staff at Baltimore from 30 workers to 200 to handle the July increase in service. About 120 of those positions will be part-time jobs.

Piedmont currently flies from BWI to New York, Charlotte and Norfolk. With the July expansion, those cities will be joined by Detroit, Cleveland, Providence, Boston, Raleigh, Charleston, Greensboro, Tampa, Miami and Hartford, Conn.