"Operation Clockwork" is the largest single-day schedule redesign in aviation history. Changes at Atlanta and Dallas/Ft. Worth restructure more than 51 percent of Delta’s network for better on-time departures, reduced airport congestion and free up aircraft for Delta's expanding route system. On Sept. 14, Delta files for reorganization under Chapter 11 of the U.S. Bankruptcy Code. In late November, Delta starts one of the largest one-month expansions in its history with service on seven new Latin American and Caribbean routes.