The Williamsport Regional Airport on Wednesday. KAREN VIBERT-KENNEDY/Sun-Gazette Commercial air service is not expected to return to the Williamsport Regional Airport until at least late summer, according to airport director Richard Howell. The hope had been to have in place commercial flights by this month, with Southern Airways serving the area. However, Howell confirmed at this week’s Williamsport Municipal Airport Authority meeting that it won’t happen now. “It is kind of disappointing,” he said. Southern had planned on flying nine-passenger planes out of the airport three times a day. He explained that Southern decided to hold off from the Williamsport market after SkyWest Airlines announced plans…