Provincetown-Boston Airlines (IATA: PT, ICAO: PBA, Call sign: PBA) (PBA) was an airline that operated between 1949 and 1989. The airline operated a route network in New England, New York, Pennsylvania, and Florida, and at one time was the largest commuter airline in the United States before its purchase by People Express Airlines and then eventual consolidation with other commuter airlines into Continental Express, now United Express after its merger.