On February 13, 2008, the pilots of a go! CRJ200 fell asleep and overshot their destination airport by before air traffic control was able to make contact with the aircraft. The incident happened on the third consecutive day during which the pilots had been required to start duty at 0540 am. The captain suffered from an undiagnosed severe sleep apnea. The National Transportation Safety Board determined the probable cause of this incident as follows: "The captain and first officer inadvertently falling asleep during the cruise phase of flight. Contributing to the incident were the captain's undiagnosed obstructive sleep apnea and the flight crew's recent work schedules, which included several consecutive days of early-morning start times."