No fatalities

21 Jul 2017: ROBINSON HELICOPTER COMPANY R22 MARINER — ROCKY MOUNTAIN ROTORS LLC — Bozeman, MT

Bozeman, MT, United States

On 21 Jul 2017, a ROBINSON HELICOPTER COMPANY R22 MARINER operated by ROCKY MOUNTAIN ROTORS LLC was involved in an aviation accident near Bozeman, MT. No fatalities were reported. Investigators recorded the probable cause as: The flight instructor’s unstabilized autorotation, which resulted in a hard landing. 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

During a simulated 180° right turn autorotation, the helicopter entered with excessive nose-low attitude and high descent rate. A delayed power-on recovery and flare led to a hard touchdown, resulting in a main rotor blade striking the tailboom.

Incident Overview

A helicopter experienced an accident during a training flight while the flight instructor was demonstrating simulated 180° right turn autorotations.

Sequence of Events

According to the flight instructor, during the entry of the third autorotation, the helicopter's attitude was excessively nose low and the rate of descent was high. He initiated a power-on recovery, but the flare was performed too late. He applied forward cyclic to level the skids and increased collective to its mechanical limit. Despite these actions, the helicopter touched down, and one of the main rotor blades struck the tailboom, resulting in substantial damage to that component.

Pilot Remarks

In the National Transportation Safety Board's Pilot Aircraft Accident Report, the instructor stated, "The event could have been avoided by recovering the autorotation sooner and doing a go-around."

Operator Report

The operator reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.

Contributing factors

Instructor/check pilotDescent rate — Not attained/maintainedProp/rotor parameters — Not attained/maintained