No fatalities

5 Jun 2010: ROBINSON R22 BETA — Flight School — La Verne, CA

La Verne, CA, United States

On 5 Jun 2010, a ROBINSON R22 BETA operated by Flight School was involved in an aviation accident near La Verne, CA. No fatalities were reported. Investigators recorded the probable cause as: A loss of engine power due to the pilot's inadvertent movement of the mixture control. This summary draws on records from NTSB; 17 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

A pilot accidentally pulled the mixture control while trying to adjust the trim, causing the engine to stop during approach. The helicopter autorotated but rolled onto its side at touchdown.

Incident Overview

The accident occurred during an approach when the pilot, while attempting to adjust the trim control, inadvertently activated the mixture control, resulting in an engine stoppage. The pilot stated that during the approach he noticed the trim was still on. He reached down to turn it off by feel while remaining visually focused outside the helicopter and concentrating on the approach.

Sequence of Events

The pilot reported that the trim knob was stuck in the "up" position. He applied increasing pressure until the knob moved. However, while focused on the approach, he "blindly checked the status of the trim knob" and "unintentionally and without explanation pulled the mixture control up." The pilot stated that the engine instantly turned off, and the low rotor RPM system activated. He then entered an autorotation.

Engine Stoppage and Landing

The engine stopped at a height of approximately 50 feet above ground level (agl). The helicopter touched down in the dirt and rolled onto the pilot's side. The pilot reported no mechanical failures or malfunctions prior to the accident.

Contributing factors

PilotIncorrect use/operation