NTSB Identification: SEA06LA121.
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Nonscheduled 14 CFR
Accident occurred Thursday, June 15, 2006 in Vernal, UT
Probable Cause Approval Date: 11/29/2006
Aircraft: Bell 206L, registration: N265SH
Injuries: 6 Minor.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

Prior to takeoff in conditions that resulted in a density altitude of over 10,000 feet, the pilot figured his takeoff/hover performance using the Hover Ceiling In Ground Effect chart, which indicated the helicopter could safely depart the landing zone (LZ). Because he was taking off over uneven, sloping, brush-covered terrain, he should have used the Hover Ceiling Out of Ground Effect chart, which indicated the helicopter did not have the performance to safely depart the LZ. After liftoff, the pilot started moving the aircraft forward, but it could not out-climb the up-sloping terrain, so he elected to make a precautionary landing on a nearby road. During the landing attempt, the helicopter's tail rotor lost its effectiveness, and the aircraft spun around once and descended into the terrain.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The loss of tail rotor effectiveness during an attempted precationary landing after a takeoff over uneven, sloping, brush-covered terrain. Factors include the pilot using the wrong performance chart while completing his preflight performance calculations, the uneven, sloping, brush-covered terrain, and a high density altitude.

Full narrative available

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