WASHINGTON (AP) ? Evidence gathered in an investigation of a fatal medical helicopter crash has raised questions about whether the pilot was distracted by personal text messages when he failed to refuel the helicopter before taking off and misjudged how far the aircraft could fly without more fuel.
The case, scheduled to be considered at a meeting Tuesday of the National Transportation Safety Board, underscores concerns the board has already expressed that use of cellphones and other distracting electronic devices has increasingly become a factor in accidents and incidents across all modes of transportation ? planes, trains, cars, trucks and even ships. The Aug. 26, 2011, accident near Mosby, Mo., which killed four people, appears to be the first fatal commercial aircraft accident investigated by the board in which texting has been implicated.
The pilot, James Freudenbert, 34, of Rapid City, S.D., exchanged 20 text messages with an acquaintance over a span of less than two hours before the helicopter crashed into a farm field a little over a mile from where he hoped to refuel, documents made public by NTSB show. At least three of the messages were sent and five received while the helicopter was in flight, although not in the final 11 minutes of the last leg of the flight, according to a timeline prepared by investigators.
The timeline indicates Freudenbert also exchanged text messages at the same time he was reporting by radio to a company communications center that the helicopter was low on fuel. The helicopter was on the ground at the time waiting for the patient, who was being transferred from one hospital to another, and a nurse and a paramedic to board.
Although the pilot wasn't texting at the time of the crash, it's possible the messaging took his mind off his duties, interrupted his chain of thought and caused him to skip safety steps he might have otherwise performed, experts on human performance and cognitive distractions said. People can't concentrate on two things at once; they can only shift their attention rapidly back and forth, the experts said. But as they do that, the sharpness of their focus begins to erode.
"People just have a limited ability to pay attention," said David Strayer, a professor of cognitive and neural science at the University of Utah. "It's one of the characteristics of how we are wired."
"If we have two things demanding attention, one will take attention away from other," he said. "If it happens while sitting behind a desk, it's not that big of a problem. But if you are sitting behind the wheel of a car or in the cockpit of an airplane, you start to get serious compromises in safety."
In October 2010, two Northwest Airlines pilots overflew their destination of Minneapolis-St. Paul International Airport by 100 miles while they were engrossed in working on flight schedules on their laptops.
A text message ? especially one accompanied by an audible alert like a buzz or bell ? interrupts a person's thoughts and can be hard to ignore, said Christopher Wickens, a University of Illinois professor emeritus of engineering and aviation psychology. If the subject of the email is especially engaging, or especially emotional, that also makes it hard to ignore, he said.
The helicopter was operated by a subsidiary of Air Methods Corp. of Englewood, Colo., the largest provider of air medical emergency transport services in the U.S. The company's policies prohibit the use of electronic devices by pilots during flight.
Freudenbert apparently didn't check the amount of fuel on board the helicopter before taking off from the company's base in St. Joseph, Mo., even though he had been briefed that the aircraft would be low on fuel because it had been used the night before for training exercises. He radioed that he had two hours of fuel shortly after the helicopter was airborne.
But when the helicopter landed less than 10 minutes later in Bethany, Mo., to pick up the patient, Freudenbert radioed the communications center again to report that the copter was lower on fuel than he had initially thought. He estimated he had about 45 minutes worth of fuel, and said he didn't want to use any of the 20 minutes of reserve fuel federal regulations require be maintained. Investigators calculate he actually had 33 minutes worth of fuel left at that point.
Freudenbert opted to continue the patient transfer to a hospital in Liberty, Mo., changing plans only enough for a stop at an airfield a few miles closer than the Liberty hospital. The helicopter stalled and crashed at 6:41 p.m. CDT on a clear summer evening before reaching the airfield. A low fuel warning light might have alerted Freudenbert to his true situation, but the light was set on "dim" for nighttime use and may not have been visible. A pre-flight check by the pilot, if it had been conducted, should have revealed the light was set in the wrong position, investigators were told.
___
Online:
National Transportation Safety Board: http://www.ntsb.gov/safety/mwl3_2012.html
___
Follow Joan Lowy on Twitter: http://www.twitter.com/AP_Joan_Lowy
Associated Press2012 westminster dog show abe lincoln vampire hunter xi jinping matt bomer westminster kennel club dog show jeremy lin game winner chocolate covered strawberries
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.