What happened
During a specialized mission to inspect small-scale power lines, a helicopter crew attempted to maneuver around a higher-voltage power line. After successfully passing over one of the poles supporting the larger line, the crew intended to turn back toward a previously bypassed pole that required closer assessment.
As the aircraft initiated a right turn, the crew encountered challenging environmental conditions, including low cloud bases, strong winds, and a tall hill positioned directly ahead. While performing the turn into a tailwind at low airspeed on the leeward side of the hill, the aircraft lost altitude and struck the ground. The impact caused the helicopter to tip forward and strike the terrain with its rotor blades, eventually coming to rest on its left side. The aircraft sustained substantial damage, though the engine was shut down and the crew evacuated without injury. No fire occurred during the incident.
The investigation
The Swedish Accident Investigation Authority examined the circumstances surrounding the maneuver and the environmental factors present at the time of the accident. The investigation focused on the flight path, the aerodynamic challenges posed by the terrain, and the meteorological conditions. Investigators found no evidence of technical malfunctions or mechanical failures contributing to the crash.
Findings
- The accident was driven by meteorological conditions that restricted the available maneuvering space within the specific terrain.
- The combination of low cloud ceilings, high winds, and the presence of a large hill limited the pilot's ability to execute the necessary turn.
- The aircraft's power availability during the turn was insufficient to maintain altitude and avoid ground contact.