While waiting on the ground in Bethany for the patient and the medical crew, Freudenberg exchanged text messages as he was reporting by radio to a company communications center that the helicopter was lower on fuel than he had originally thought. He told the communications center he had about 45 minutes worth of fuel, which investigators said they believe was a lie intended to cover up his earlier omissions and that he was in jeopardy of violating federal safety regulations.
In fact, the helicopter had 30 minutes of fuel left, investigators said. Federal Aviation Administration regulations require 20 minutes of reserve fuel at all times.
With no other place nearby to refuel, Freudenberg opted to continue the patient transfer to a hospital in Liberty, Mo., changing his flight plan enough for a stop at an airfield 32 minutes away for fuel. The helicopter stalled and crashed 30 minutes later.
A low fuel warning light might have alerted him 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 said.
The board also said Freudenberg failed after losing engine power to set the helicopter up for a maneuver called autorotation, which employs updrafts to keep the rotor turning and permit the craft to glide to the ground. However, investigators said the pilot had only 2 seconds to complete three steps necessary for autorotation.
Although the Freudenberg wasn't texting at the time of the crash, it's possible the messaging took his mind off his duties and caused him to skip safety steps he might have otherwise performed, said experts on human performance and cognitive distraction. 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."
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 pilot didn't have a history of safety problems and was regarded as a good, safe pilot by his co-workers. He was a former Army pilot, and NTSB investigators said his actions on the day of the accident were apparently "out of character."
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