By Mary Grady, Contributing editor
A helicopter that crashed in Idaho in 2010, killing the pilot and two wildlife biologists on board, was brought down by a stray metal clipboard that hit the tail rotor, the NTSB said in its final report last week. Two scientists planned to conduct an aerial wildlife survey in a commercially owned Hiller UH 12E helicopter equipped with a three-abreast bench seat and a fully enclosed cabin, the NTSB said. The pilot stowed most of the biologists' gear on the helicopter's external racks, and all three boarded the helicopter, with the biologists in each of the outboard seats. About a half hour later, the pilot broadcast that the helicopter was "landing at Kamiah," about 35 miles short of the planned destination, and moments later, the aircraft began to break up in the air.
The investigators found that the metal clipboard struck the tail rotor and caused it to separate, causing loss of control of the aircraft. Witnesses said the helicopter was rotating as it descended. It left a 1,500-foot debris field and crashed into the driveway of a residence. The investigators weren't able to tell if the clipboard had been part of the gear stowed externally, or if a passenger had opened a door in flight and the clipboard had fallen out. The clipboard also might have been inadvertently left unsecured on one of the external racks. One witness said the right cabin door was open in flight, the NTSB said, but it appeared that both doors were closed at the time of impact.