No fatalities

26 Feb 2011: HILLER UH-12E — Colusa, CA

Colusa, CA, United States

On 26 Feb 2011, a HILLER UH-12E was involved in an aviation accident near Colusa, CA. No fatalities were reported. Investigators recorded the probable cause as: The pilot's failure to maintain an adequate airspeed and an inadvertent encounter with settling with power while flying downwind. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

A helicopter conducting a reconnaissance flight over an almond orchard entered a settling with power condition and struck trees with its main rotor blades. The pilot reported no mechanical malfunctions.

Incident Overview

The pilot of a helicopter reported that he and the owner were conducting a reconnaissance flight in preparation for a possible frost control flight the following morning. They were flying in the vicinity of an almond orchard, attempting to identify potential obstacles in the area.

Flight Maneuvers

The departure was west of the accident site and near the almond orchard. As the helicopter flew slowly over the north edge of the orchard, the pilot initiated a descent and slowed the helicopter to just above effective translational lift. He then turned southbound and noted a tailwind of 7 to 10 miles per hour.

Loss of Lift

The pilot reported that the tailwind, coupled with the descent, caused the helicopter to enter a settling with power condition. Due to the close proximity of the trees, the pilot stated that he was unable to perform a normal recovery, which would have involved lowering the collective and applying forward cyclic control.

Collision with Trees

The helicopter descended between a row of trees, and the main rotor blades struck the trees. The pilot reported that there were no mechanical malfunctions with the helicopter before the accident.

Contributing factors

PilotDescent rate — Not attained/maintainedAirspeed — Not attained/maintained