North State Aviation has notified the state that it will permanently close its facility at the Smith Reynolds Airport in Winston-Salem starting this week and lay off 345 people due to an “unforeseeable significant downturn in business.”

Company officials said in a WARN (Worker Adjustment and Retraining Notification) filing that North State was not successful in obtaining capital to avoid or postpone “this unfortunate result.”

Gary Smith, CEO of North State since last year, did not immediately respond…