South Korean Army Cobra helicopter crash caused by engine defect

An investigation into the February crash of a Republic of Korea Army AH-1S Cobra attack helicopter in Gapyeong has identified an engine cylinder defect as the direct cause. The Central Accident Investigation Committee announced that a deformation in the internal cylinder of the exhaust diffuser caused the engine to stop mid-air.

The failure led to a misalignment of the cylinder axis, causing the power shaft and compressor shaft to frictionally contact. This generated intense heat, resulting in the shafts seizing together. Investigators noted that the pilots attempted an emergency landing to avoid residential areas, turning the nose 42 degrees to the left before the impact.

The engine, which had been in service for over 30 years, likely suffered from accumulated fatigue. Ozark, the holder of the engine's copyrights, participated in the investigation and was asked to adjust inspection cycles and redesign shaft clearances.

In response, the Army is considering accelerating the retirement of the aging Cobra fleet. This decision must be coordinated with the Joint Chiefs of Staff, especially as the replacement Light Armed Helicopter (LAH-1 Mirion) has also faced engine-related flight suspensions. Additionally, the Army plans to strengthen its safety management system by transferring oversight to the Army Headquarters Combat Readiness and Safety Group by April 2027.