NTSB report details fatal-free rotor damage to Alaska sling-load helicopter

The US National Transportation Safety Board published a safety investigation report on 23 October 2025 into an accident involving an Airbus AS350B3 helicopter, registration N589SH, operated by Soloy Helicopters.

The accident occurred on 20 August 2025 near Skwentna, Alaska, during a helicopter external sling load operation carried out under FAA Part 133 rules. The aircraft had been delivering drilling equipment to a remote mining exploration site in mountainous terrain, according to the operator's accident report.

According to that account, the pilot, who held roughly 15,500 total flying hours with about 9,900 on the type, landed to allow drillers to be picked up after the load had been delivered. While the helicopter idled with controls locked, the pilot got out to roll up the Kevlar longline, which became caught on a rock in the uneven terrain.

When the pilot pulled to free the line, it released suddenly off a sharp rock edge and swung up into the main rotor blades, the report states. The resulting imbalance tore the main gearbox and rotor system from the helicopter, destroying it.

The operator said it has since issued an operations directive in response to the occurrence, though further details of that directive were not included in the material reviewed. No information on injuries to those involved was specified in the extract available.