What happened
On 6 November 2009, a KA-32A helicopter, registration HL9405, operated by Changwoon Aviation, crashed on the upper ridge of Mt. Jeombong in Inje-gun, Gangwon-do. The aircraft was engaged in a cargo airlifting mission, transporting lumbered trees and equipment for a power line construction project.
During the mission, the crew was moving between various installation points. While performing a climbing turn, the aircraft entered a cloud layer, causing the crew to lose their sense of direction. During this maneuver, the external cargo—consisting of several large trees—became entangled in the trees on the mountain ridge. This entanglement caused the aircraft to strike the terrain and subsequently triggered a fire that completely destroyed the wreckage. Both the captain and the co-pilot perished in the accident.
The investigation
The ARAIB investigation examined the flight history, weather conditions, and the operational procedures of the operator. Investigators reviewed the aircraft's maintenance logs, which showed no mechanical defects in the engines or control systems prior to the flight. The investigation also focused on the crew's training, specifically regarding instrument flight and Crew Resource Management (CRM).
Furthermore, the board analyzed the impact of the post-crash fire, which destroyed the flight data recorder (FDR) because of its proximity to the fuel tank. The investigation also looked into the fuel management practices of the crew, noting that the aircraft had not been refueled at an appropriate interval during the mission.