History of the Flight
On October 19, 2011, at about 14:10 Korean Standard Time, a B214B-1 helicopter registered as HL9131, operated by Hongik Air Service Co., Ltd., crashed while moving for airlift operations in Sammun-ri, Jangyu-myeon, Gimhae-si, Gyeongsangnam-do. The aircraft, a rotorcraft for aerial work, was conducting visual flight rules operations to transport construction materials for power-line tower construction between Gimhae and Noksan.
Injuries and Damage
The two pilots aboard—a captain and a co-pilot—were seriously injured. The helicopter was destroyed by the impact of the crash.
Probable Cause
The Aviation and Railway Accident Investigation Board (ARAIB) determined that the probable cause of the accident was that the sling strap attached to the belly hook entered the tail rotor blade because the captain decelerated more than normal and descended simultaneously while flying at approximately 70 knots.
Contributing Factors
The investigation identified two contributing factors: (1) Hongik Air Service provided inadequate flight procedures training for airlift operations, and (2) the flight route taken by the captain on the day of the accident was unsuitable due to numerous obstacles.