MYRTLE BEACH, S.C. (AP) — The largest airline serving Myrtle Beach is adding flights and will start using bigger planes to serve the resort that is the heart of South Carolina's $15 billion tourism industry.

Spirit Airlines said Tuesday it plans nonstop, daily flights to Philadelphia and Baltimore-Washington International Airport starting April 25. Tourism officials say the flights will give visitors and residents more travel options.

Spirit carries about half the passengers coming through the Myrtle Beach airport.

The airline also plans to start using bigger planes to serve Myrtle Beach.

Local officials say that could turn around declining passenger numbers at the airport. Those numbers were down 16 percent last year.