A Mesa Airlines CRJ200 pilot with undiagnosed severe sleep apnoea told NTSB investigators that he had intentionally "napped in the cockpit" about once per week during a temporary assignment flying for Mesa's Hawaii-based subsidiary, go! Airlines.
The captain's fitness is a key element in a 13 February 2008 incident in which both pilots of go! flight 1002 "inadvertently" fell asleep during what was expected to be a 40min morning flight from Honolulu to Hilo, Hawaii at a cruise altitude of 21,000ft. go! operated five CRJs with a support staff of 60 pilots at the time of the incident.
Air traffic controllers and other pilots could not communicate with the CRJ for approximately 18min after the crew belatedly responded to a clearance to change course after takeoff from Honolulu.
"Working as hard as we had, we tend to relax," the 53-yr-old captain told NTSB investigators in a recently released factual report on the incident by the agency. "We had gotten back on schedule [after a 30min departure delay due to a flight attendant scheduling issue], it was comfortable in the cockpit, the pressure was behind us. The warm Hawaiian sun was blaring in as we went eastbound. I just kind of closed my eyes for a minute, enjoying the warm sunshine, and dozed off."
The 23-year-old first officer, who was at the controls of the aircraft on the incident segment, told the NTSB he had entered "a sleep-like state from which he could 'hear what was going on, but could not comprehend or make it click.'"
After passing the airport at Hilo, the aircraft continued flying east for 26nm over the ocean before the first officer awoke and was provided vectors back to the airport by air traffic control, according to the factual report.
The report reveals that the crew reported to FAA that they had lost communication because they had selected an incorrect radio frequency, then flew the next leg of the trip back to Honolulu before removing themselves from duty. The captain then submitted a written report to Mesa explaining that he and the first officer had fallen asleep.
The captain, on temporary assignment for Mesa in Hawaii, told the NTSB that he never before "inadvertently" fallen asleep during a flight, but that he had "intentionally" taken 20-min naps in flight about once per week during his temporary duty for go!.
The pilot said he had napped more often than once a week while flying for Mesa in the US, a statement the investigators corroborated with a first officer who had flown with him in the continental US. Mesa's senior director of flight operations told the NTSB has had been unaware of the pilot's napping habit before the incident. FAA rules allow for one of the two required pilots on a flight deck to take a "rest period" during the cruise portion of a flight.
NTSB says post-incident sleep analysis of the captain revealed a "severe obstructive sleep apnea" which a sleep medicine specialist said could cause "reduced sleep quality, daytime fatigue, and, in severe cases, cognitive dysfunction."
The medical and pathological details on the first officer do not reveal any clues as to why he also fell asleep on the flight.
Source: Air Transport Intelligence news
