Sleepy Stewart International Airport in Newburgh, N.Y., might get much busier after the Port Authority of New York and New Jersey purchases (for $78.5 million) the operating lease for the airport from National Express. The move is intended to relieve congestion at New York-area airports, which are also operated by the Port Authority, “and help us prepare for inevitable population and passenger growth,” said New York governor Eliot Spitzer. The Port Authority plans to take over operations at Stewart in October, pending a legislative change in New Jersey that would authorize the Authority to operate an airport outside of the area covered by its original charter. FBO Supermarine is owned by American Airports, which operates airports and owns FBOs, primarily in California. Stewart is also home to the Air National Guard’s 105th Airlift Wing C-5 Galaxy fleet. The Port Authority also operates La Guardia, Kennedy, Newark and Teterboro airports.