On December 21, 2009, the Department of Transportation issued final rules prescribing air carrier responsibilities in the event of lengthy tarmac delay.  The rules will require U.S. air carriers operating aircraft designed for thirty or more seats to develop and implement contingency plans to address extended delay.  Air carriers generally will have to deplane passengers after three hours and provide food and water after two hours.  The rules also require air carriers to develop and publish customer service plans.