Pinnacle Airlines was a regional airline headquartered in Memphis, Tennessee, operating as a Delta Connection carrier under contract with Delta Air Lines. The airline flew under the Delta Connection brand, providing regional feeder service to Delta's network from hubs including Minneapolis-St. Paul and Detroit. Founded in 1985 as Business Express Airlines and later rebranded, Pinnacle Airlines operated a fleet primarily composed of Bombardier CRJ regional jets. The airline expanded significantly in the 2000s and at its peak was one of the larger regional carriers in the United States. Pinnacle Airlines filed for Chapter 11 bankruptcy protection in April 2012 and ceased operations in December 2012 after failing to secure a new capacity purchase agreement with Delta Air Lines. Its assets and some operations were absorbed by other regional carriers.