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 August 26, 2011, accident near Mosby, Missouri, which killed four people, appears to be the first fatal commercial aircraft accident investigated by the National Transportation Safety Board in which texting has been implicated.

The pilot, James Freudenbert (34), of Rapid City, South Dakota, 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 the 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.

More In: World | International | News