Aviation Spirit adds Las Vegas flights from Baltimore and Philadelphia By Jerry Limone / February 01, 2013 Share 1 -- Spirit Airlines will begin daily Las Vegas service from Baltimore-Washington Airport (BWI) and Philadelphia on April 25. The flights to Las Vegas from both airports will be in the evening, and the return leg will be an overnighter. Southwest serves Las Vegas from BWI and Philadelphia, and US Airways serves Las Vegas from its Philadelphia hub. Spirit begins operations at Philadelphia on April 4, with daily service to Dallas-Fort Worth. Seasonal service to Myrtle Beach, S.C., begins April 25.