No fatalities

14 Mar 2015: ENSTROM F28 - C — Shelby, MT

Shelby, MT, United States

On 14 Mar 2015, an ENSTROM F28 - C was involved in an aviation accident near Shelby, MT. No fatalities were reported. Investigators recorded the probable cause as: The pilot's failure to maintain main rotor RPM during a low altitude operation, which resulted in a loss of aircraft control and collision with terrain. 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 impacted sloping terrain after the pilot experienced two episodes of low rotor rpm while maneuvering at low altitude. The aircraft sustained substantial damage. No preimpact mechanical failures were reported.

Accident Sequence

The pilot reported that while maneuvering at a low altitude over a machinery yard, he observed a low rotor rpm condition. When he lifted the collective, the rpm continued to bleed off, which resulted in the helicopter yawing to the left. The pilot stated that he managed to get the helicopter back under control, but then entered the low rotor rpm condition a second time. Unable to keep the helicopter flying straight, the aircraft impacted upsloping terrain with its left skid, which was followed by the main rotor blades striking the ground.

Damage

The helicopter sustained substantial damage due to the impact with terrain.

Investigation Findings

The pilot reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation.

Contributing factors

PilotProp/rotor parameters — Not attained/maintained