SPOKANE, Wash. Washington State University sleep researchers have determined that the air traffic controller in the crash of a Lexington, Ky., commuter flight was substantially fatigued when he failed to detect that the plane was on the wrong runway and cleared it for takeoff.
Writing in the journal Accident Analysis and Prevention, the researchers come short of saying his fatigue caused the accident. But they say their findings suggest that mathematical models predicting fatigue could lead to schedules that reduce the risk of accidents by taking advantage of workers' sleep schedules and biological, or circadian, clocks.
In the case of Comair Flight 5191, the air traffic controller was finishing an overnight shift with just two or three hours of sleep the previous afternoon.
"He was tired," says Gregory Belenky, a paper co-author and director of the Sleep and Performance Research Center at WSU Spokane, "and he was working a schedule that was not circadian friendly."
The Atlanta-bound Delta Connection flight crashed on takeoff shortly after 6 a.m. on August 27, 2006, killing 49 of the 50 people on board. The National Transportation Safety Board concluded the flight crew failed to detect that the plane was on a general aviation runway half as long as the assigned runway.
Bluegrass Airport's lone air traffic controller had cleared the plane for takeoff. But the WSU researchers stress that they are not fixing blame for the crash on him, nor can they say if his fatigue was the cause of the accident.
"We're identifying times of day that are relatively more dangerous than other times of day," says Lora Wu, a Sleep and Performance Center research assistant and co-author of the paper. "We're not trying to place blame on any of the individuals involved."
The researchers used a mathematical model to analyze the controller's work history, which consisted of two evening shifts, two day shifts and the overnight shi
|Contact: Gregory Belenky|
Washington State University