NTSB Identification: LAX06CA296.
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Accident occurred Monday, September 18, 2006 in Angels Camp, CA
Probable Cause Approval Date: 01/31/2007
Aircraft: Bell 47G, registration: N7762
Injuries: 2 Uninjured.
NTSB investigators used data provided by various entities, including, but not limited to, the Federal Aviation Administration and/or the operator and did not travel in support of this investigation to prepare this aircraft accident report.
During an approach to land on a flat clear-cut plateau near a local vineyard, the wind shifted and the helicopter landed hard coming to rest on its left side. The pilot noted various obstacles at the approach end of the landing zone; two trees about 50 feet apart from each other, which he intended to fly between, a 6-foot-high mound, followed by a 2-foot hole, and another 2-foot mound, and then a flat area with no additional obstacles. On the approach, the wind shifted from a headwind to a tail wind. The pilot reported that the airspeed dropped below ETL (effective translational lift) and resulted in a loss of lift. He pushed the cyclic forward to gain forward airspeed and applied cyclic and power to avoid contacting the terrain below the top of the plateau. This maneuver assisted in gaining altitude, placing the helicopter above the plateau, but not above the 6-foot mound. He flared the helicopter, and as it passed over the mound, the tail rotor guard struck the top of the mound, which placed the helicopter in a nose down attitude. One of the landing gear skids collided with the 2-foot mound, which broke off the tailboom. At that point, the helicopter yawed to the right and started to roll to the left, and came to rest about 5 feet from the mound, lying on its left side.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: a hard landing due to the pilot's inadequate compensation for a wind shift encountered on final approach and his failure to maintain an adequate translational lift airspeed. Full narrative available
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