Engine shutdown caused fatal Army helicopter crash in Feb.: military

A sudden engine failure caused the deadly crash of an Army helicopter in February, resulting in the deaths of two soldiers, according to military officials. The AH-1S Cobra helicopter, part of an Army aviation unit, crashed during an emergency landing training exercise in Gapyeong County, located about 55 kilometers northeast of Seoul, on February 9.

The two warrant officers on board were killed in the incident, with no civilian damage reported. The military has been investigating the cause of the crash, which was eventually attributed to internal misalignment of a cylinder in the helicopter engine. This misalignment led to the central drive shaft wobbling as it rotated, creating violent vibrations known as shaft whirling.

When the pilot attempted to regain altitude by increasing throttle, the spinning power shaft collided with another spinning shaft, causing extreme heat to build up and melt the engine components. This ultimately led to the engine shutting down. Military officials have concluded that internal cylinder misalignment was the primary cause of the accident.