Synopsis
On 1 November 2022, at 1726 UTC, an AgustaWestland AW109SP helicopter, registration G-RAYN, struck trees while climbing away from an unlit field landing site near Nantclwyd Lodge, Llanelidan, Denbighshire. The main rotor blades sustained catastrophic damage, causing the helicopter to fall to the ground and come to rest on its right side. There was no fire, and the pilot shut down both engines before helping passengers escape. One passenger was seriously injured; four others sustained minor injuries. The pilot was uninjured.
History of the Flight
The pilot departed Biggin Hill at 0727 hrs that morning with approximately 600 kg of fuel, flying to Lisvane (near Cardiff) to collect five passengers. After an uneventful flight to the field landing site (operator code LEA2), the helicopter landed at 0920 hrs. The pilot then flew to Hawarden Airfield to refuel, returning to LEA2 later. The return flight was scheduled for 1630 hrs, but the passengers delayed departure until about 1715 hrs. Sunset was at 1645 hrs, and the end of civil twilight at 1718 hrs, making the takeoff a night departure. The landing site was unlit, but the pilot assessed the visual references as sufficient.
Accident Sequence
After lifting into a hover, the pilot translated forward and left to increase separation from the treeline and turned into wind. At approximately 30–40 ft above ground level, the pilot felt a massive jolt and attributed it to a rotor head imbalance. The helicopter shook violently and fell to the ground. Witnesses at the treeline reported no unusual sounds or sights before the strike. The helicopter came to rest at the base of a tree, with the tail boom separated and debris from rotor blades and branches scattered around.
Injuries and Damage
The helicopter was destroyed. One passenger suffered serious injuries and was hospitalized for several months. Four passengers received minor injuries; the pilot was not injured. Of the five passengers, at least four had not fastened their seatbelts prior to departure.
Investigation Findings
The investigation identified no causal or contributory technical factors. The accident resulted from the unintended rearward transition of the helicopter into a stand of trees during a planned vertical departure at night from an unlit field. The pilot did not complete auditable weight and balance calculations before departing Biggin Hill, potentially contributing to the helicopter being overweight for the return flight. The visual cues available at night were inadequate for detecting the rearward drift. The pilot carried out a strategic pre-flight risk assessment but did not use a more tactical Threat and Error Management approach for each phase. The operator has since taken safety action to improve night flying procedures, ground equipment, and training.