What happened
On 21 March 1998, an Enstrom 480T, registration G-TECN, was preparing for departure from its operating base near Killochries Fold, Kilmacolm. The aircraft had been parked facing a westerly heading, positioned near a hedge and a barn. Given the calm wind conditions, the pilot intended to depart by either hovering backwards or performing a right-hand pedal turn to clear nearby obstructions before heading southeast.
As the pilot lifted the helicopter into a hover and initiated a small pedal turn to the right, the aircraft remained under control and properly trimmed. However, during the continuation of this maneuver, the helicopter suddenly became uncontrolled. The pilot subsequently experienced a tail rotor impact with a farm gate located to the east of the initial parking spot. This impact caused the helicopter to spin to the right and roll onto its right side on the ground. All four occupants (one crew member and three passengers) were able to unfasten their seatbelts and exit the aircraft without injury.
The investigation
The investigation, prompted by the pilot's accident report, examined the aircraft's positioning and the sequence of the maneuver. Investigators reviewed the meteorological conditions, noting an anticyclone was centered near the area, resulting in high visibility and calm to variable winds. The investigation also considered the aircraft's operating limitations, which permit sideward and rearward maneuvering up to 35 kt, noting that no specific wind azimuth is critical for directional control.
Findings
- The primary cause of the accident was a tail rotor strike against a farm gate.
- The aircraft sustained extensive damage that rendered it beyond economic repair.