Primary finding
Probable cause
The pilot's failure to maintain an adequate airspeed and an inadvertent encounter with settling with power while flying downwind.
Investigator assessment
Analysis narrative
The pilot reported that he and the owner of the helicopter were flying a reconnaissance flight in preparation for a possible frost control flight the following morning. They were attempting to identify potential obstacles in the area. As they were flying slowly over the north edge of an almond orchard he initiated a descent, and slowed the helicopter to just above effective translational lift. He turned southbound and noted a 7- to 10-mile-per-hour tailwind. He reported that the tailwind, coupled with the descent, caused the helicopter to enter a settling with power condition. He stated that due to the close proximity of the trees he was not able to perform a normal recovery of lowering the collective and applying forward cyclic control. The helicopter descended between a row of trees and the main rotor blades struck the trees. The pilot stated that there were no mechanical malfunctions with the helicopter before the accident.
Source record
Factual narrative
The pilot reported that when the accident occurred he and the owner of the helicopter were flying a reconnaissance flight in preparation for a possible frost control flight the following morning. They were attempting to identify potential obstacles in the area. The departure was west of the accident site and near an almond orchard. As they were flying slowly over the north edge of the orchard the pilot initiated a descent, as well as slowing the helicopter to just above effective translational lift. He turned southbound and noted a 7- to 10-mile-per-hour (mph) tailwind. The pilot reported that the tailwind, coupled with the descent, caused the helicopter to enter a settling with power condition. He stated that due to the close proximity of the trees he was not able to perform a normal recovery of lowering of the collective and applying forward cyclic control. The helicopter descended between a row of trees and the main rotor blades struck the trees. The pilot stated that there were no mechanical malfunctions with the helicopter before the accident.