The crash of an emergency medical transport helicopter in Missouri in 2011, which killed all four aboard, occurred in part because the pilot was distracted by texting and calling from his cell phone during the flight, the US National Transportation Safety Board (NTSB) ruled yesterday, concluding its investigation into the accident. Earlier, the NTSB was reported to be examining the pilot's texting as a possible cause of the crash, but now the agency has officially declared it one of four "contributing factors." The grim news is thought to be the first time in the US that texting has been linked to a fatal aviation disaster.

The actual technical cause of the helicopter crash was an engine flameout, which resulted from the pilot failing to refuel before he picked up the three passengers — a patient with a life-threatening condition and two medical personnel — from a hospital in Bethany, Missouri. Still, the pilot, who said he hadn't slept well the night before, tried to fly the helicopter to another hospital 62 miles away (about 30 minutes). "The helicopter ran out of fuel and the engine lost power within sight of the airport," the NTSB noted. Regarding the pilot's cell phone use, which the NTSB graphed in detail, the agency had this to say:

"An examination of cell phone records showed that the pilot had made and received multiple personal calls and text messages throughout the afternoon while the helicopter was being inspected and prepared for flight, during the flight to the first hospital, while he was on the helipad at the hospital making mission-critical decisions about continuing or delaying the flight due to the fuel situation, and during the accident flight."

The NTSB further notes that when the engine died, the pilot wasn't using his phone. But "the texting and calls, including those that occurred before and between flights, were a source of distraction that likely contributed to errors and poor decision-making." Still, the texting was just one of the four contributing factors cited, the other three were the pilot's fatigue, the pilot's lack of proper training for how to safely land an aircraft that had run out of fuel, and the helicopter company Air Methods' failure to require automatic notification of unusual fuel readings in its aircraft. But in summarizing the findings, NTSB Chairman Debora Hersman called out digital distractions in particular, saying "this investigation highlighted what is a growing concern across transportation, distraction and the myth of multi-tasking."