Question: Raleigh–Durham International Airport, is the main airport serving Raleigh, Durham, and the surrounding Research Triangle region of North Carolina, the airport  is a crew base for which regional airline carrier, owned by Trans States Holdings and is headquartered in Bridgeton, Missouri?
Sentence (from "Research Triangle"): A 2013 Census estimate put the population at 2,037,430, making it the second largest metropolitan area in the state of North Carolina behind Charlotte.
Relevant evidence: No