Mesaba Aviation, Inc. (operating as Mesaba Airlines) was an American regional airline based in Eagan, Minnesota The airline was a wholly owned subsidiary of Pinnacle Airlines Corporation. Its flights operated as Delta Connection for Delta Air Lines and US Airways Express for US Airways. Previously, the airline operated as Northwest Airlink and Northwest Jetlink on behalf of Northwest Airlines which subsequently merged with Delta. Mesaba Airlines effectively ceased operations on January 4, 2012, when all aircraft and personnel were transitioned to the Pinnacle Airlines operating certificate. Mesaba's operating certificate was surrendered on July 31, 2012.