What happened
On July 1, 2023, a Bell 206 B3 helicopter, registration SE-JOD, was preparing for a commercial flight in Adolfström, Norrblotten County. The aircraft, operated by Fjällflygarna i Arjeplog AB, was positioned on a specialized transport carriage for a scheduled passenger pickup.
As the pilot initiated the lift-off, the helicopter shifted or pivoted toward the right. During this movement, the right landing gear plate made contact with an edge rail mounted on the side of the carriage. This contact obstructed the aircraft's movement, causing the helicopter to roll sharply to the right. The main rotor struck the asphalt, resulting in the tail boom breaking off and the main rotor gearbox separating from the fuselage. The pilot successfully evacuated the aircraft through the front window, and no injuries were reported, though the aircraft suffered extensive damage.
The investigation
Investigators from the Swedish Accident Investigation Authority (SHK) examined the accident site, the wreckage, and the transport carriage. The inquiry focused on the mechanics of the lift-off and the equipment used during the operation.
Technical analysis revealed that the helicopter was equipped with landing gear plates designed to prevent the skids from sinking into soft ground. However, these plates were "home made" and lacked the necessary certification or supplemental type certificate (STC) required for aircraft modifications. The investigation also looked into the design of the carriage, which featured edge rails intended to prevent the aircraft from sliding off during slippery conditions.
Findings
- The primary cause of the accident was the operator's failure to sufficiently manage the risks of taking off from a carriage, particularly when using a pilot with limited recent experience.
- The right landing gear plate became caught on the carriage's edge rail during the lift-off sequence.
- This obstruction triggered a dynamic rollover, a condition where the rotor thrust intensifies the roll once a critical angle is exceeded, making recovery impossible.
- The use of uncertified, non-standard landing gear plates and the presence of the carriage's edge rails may have contributed to the event.
Safety action
Following the accident, the operator conducted an internal review and implemented several changes. These include updating procedures for landing on carriages and removing the edge rails from the transport equipment. The operator also notified all staff regarding the specific risks associated with take-off maneuvers on such platforms.