Two commercial airline pilots, who fell asleep while on duty in February this year, have been reinstated as pilots after they were confirmed to have been diagnosed as suffering from Obstructive Sleep Apnoea (OSA). See here.
The two, who were commandeering a 45 min commercial flight operated by Go! Airlines from Honolulu to Hilo on February 13 carrying 40 passengers, overflew their destination at 21,000 feet and alarmed air traffic controllers when they received no response. Finally, when contact was established after one of them woke up, the plane landed safely.
The US Federal Aviation Authority (FAA) suspended them for up to 60 days for careless and reckless operation of an aircraft and for failing to maintain radio communications but allowed them to resume duties from 9 September, presumably because they had received treatment for OSA and certified fit.
This incident highlights a rather newly-recognised medical condition which causes people to snore and stop breathing repeatedly in their sleep, causing them to feel extremely drowsy the next day. I have even encountered cases of chauffeurs presenting with chest-pain due to chest injury , the result of them falling asleep at the wheel and crashing their cars! Please see my earlier post to know more about OSA, the medical version.