The NTSB says the FAA should require aviation medical examiners to evaluate pilots for risk factors of obstructive sleep apnea and ask about any previous diagnosis of the disorder. The recommendation (click here for a PDF) followed the board's investigation of an incident in February 2008 in which both crew members on a go! airlines flight in Hawaii fell asleep in the cockpit during the cruise phase of an inter-island flight and overflew their destination. The NTSB investigation found the captain's undiagnosed obstructive sleep apnea was a contributing factor. In its safety recommendation, the NTSB said the FAA should implement a program to identify pilots at high risk for obstructive sleep apnea and require that those pilots provide evidence of having been appropriately evaluated and effectively treated, if treatment is deemed necessary, before being granted unrestricted medical certification. No injuries resulted from the go! airlines incident. Both pilots lost their jobs.
The NTSB investigation of the incident also named as a contributing factor the flight crew's recent work schedules, which included several consecutive days of early-morning start times. This likely caused the pilots to receive less daily sleep than is needed to sustain optimal alertness and resulted in increased levels of daytime fatigue, the NTSB said. The board also said the FAA should conduct research examining how pilot fatigue is affected by the unique characteristics of short-haul operations and identify methods for reducing those effects, including research into the interactive effects of shift timing, consecutive days of work, number of legs flown, and the availability of rest breaks. The go! airlines crew had been flying starting at 05:40 for three days in a row, and the NTSB cited a NASA report showing that early start times make it harder for flight crews to get adequate sleep. The pilots were also flying eight legs a day, the NTSB said, requiring many high-workload takeoffs and landings.