The National Transportation Safety Board has issued a report on what may have caused a fatal experimental aircraft crash in western Iowa’s Cass County late last year.

A Wiota man, 39-year old Stephen Merk, died when the Bruce Protech P-T-2-B aircraft he was piloting, crashed shortly after takeoff from the Anita airport on November 6th, 2004. The N-T-S-B report says Merk was conducting high-speed taxi runs on the runway the morning of the crash, when he decided to take-off. Shortly afterward, the amateur-built aircraft Merk recently purchased made a sharp bank and dove nose-first into the ground.

A witness reported the plane was in a turn when the engine suddenly “stalled out or quit.” Another witness said there was a “sputter” sound, like the pilot was attempting to restart the aircraft, just before the crash. A post-crash inspection of the plane failed to reveal any obvious reason for the crash and toxicology tests on the body of the pilot turned up negative. Investigators say although the weather at the time was clear the temperatures aloft could have caused the engine’s carburetor to ice-over, and likely resulted in the crash.