Tri Cities Regional Airport Is Slowly Growing Revenues And Passengers. According To Executive Director Patrick Wilson, The Industry Stabilization Is Keeping The Doors Open At The Airport. Since 1978, Mergers Have Whittled 20 Major Air Carriers Down To Just Four – Delton, United Airlines, Southwest, And American Airlines. Despite The Fact That Airlines Aren’t Adding New Flights Out Of The Tri, About 216-Thousand Travelers Are Projected To Use The Facility In The Current Fiscal Year.