Two airline pilots fell asleep while cruising over Hawaii last February, flying past their destination toward open ocean for 18 minutes before waking up and returning for a safe landing, federal accident investigators revealed Tuesday.
That incident and an accident in Traverse City, Mich., last year highlight the need for more comprehensive rules to stem the growing list of crashes attributed to the lengthy hours that pilots routinely work, the National Transportation Safety Board (NTSB) said. Crashes linked to fatigue have killed 249 people since 1997, according to NTSB records.
"It's an insidious issue," NTSB Chairman Mark Rosenker said. "Many times the pilots themselves don't recognize that they are fatigued when they get into that cockpit."
The NTSB voted to recommend that federal aviation regulators and airlines use fatigue studies to rewrite the rules for how long pilots can legally fly. Currently, federal law allows pilots to work up to 16 hours a day, including up to eight hours behind the controls, and loopholes allow longer days in some situations.
Air-traffic controllers frantically radioed Go Airlines Flight 1002 from Honolulu to Hilo, Hawaii, for 18 minutes on Feb. 13, but got no response from the pilots, said NTSB investigator Jana Price.
In the safety board's first disclosure of details from the investigation, Price said both pilots "unintentionally fell asleep" as the Bombardier CRJ-200 jet flew at 21,000 feet. The jet carried 40 passengers.
The two pilots had been flying together for three arduous days "that involved early start times" and a "demanding" sequence of short flights, Price said. Since the incident, the captain had been diagnosed with severe obstructive sleep apnea, she said. Apnea causes people to repeatedly wake up during the night and has been linked to poor work performance and accidents.
In a separate investigation, the NTSB concluded that a regional airline crash last year in Traverse City was probably triggered by fatigue. Pinnacle Airlines Flight 4712 skidded off the end of a snowy runway on April 12, 2007, after landing in the early hours of the morning. None of the 49 passengers, two pilots and a flight attendant were injured.
The NTSB found that the pilots of the Bombardier CRJ-200 should never have attempted the landing.
The runway was too slick to land under the airline's rules, but the pilots failed to perform a basic landing calculation and missed other warning signs that the weather was deteriorating.
The accident happened after the pilots had worked 14 hours. The cockpit recorder overheard the pilots yawning and the captain made repeated references to being tired, the NTSB found.
The NTSB has been calling for reform of pilot work rules for decades. Several attempts to rewrite pilot work rules have failed in the face of opposition from airlines and pilot groups.