No fatalities

29 Aug 2011: ENSTROM F-28F — ENSTROM HELICOPTER CORP — Menominee, MI

Menominee, MI, United States

On 29 Aug 2011, an ENSTROM F-28F operated by ENSTROM HELICOPTER CORP was involved in an aviation accident near Menominee, MI. No fatalities were reported. Investigators recorded the probable cause as: The pilot's failure to maintain control of the helicopter during a hover. This summary draws on records from NTSB; 4 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

During a test flight to measure collective stick forces with the bias disabled, the pilot lost control while positioning a force gauge, resulting in a hard landing that damaged the tail rotor blades and drive shaft.

Introduction

A company test flight aimed to measure collective stick forces with the collective bias disabled. The pilot, who was the sole occupant, conducted the flight.

Flight Details

The pilot lifted the helicopter into a hover and then hovered free of obstacles. He reported that the collective controls were heavy, as anticipated, but the helicopter remained controllable.

Accident Sequence

While attempting to position a force gauge between his hand and the collective grip, the pilot lost control of the helicopter. The helicopter subsequently landed hard onto the ramp. The tail rotor blades struck the ramp, and the helicopter came to rest upright.

Postaccident Findings

Examination of the helicopter after the accident revealed bent tail rotor blades and a sheared tail rotor drive shaft.

Pilot's Comments

The pilot stated that he should have taken an observer or other personnel on the flight to assist while he focused on flying the helicopter.

Contributing factors

Performance/control parameters — Not attained/maintainedPilot