Accident Overview
On September 16, 2013, at approximately 13:48 Japan Standard Time, a Bell 412EP helicopter registered as JA20NA, operated by the Nara Disaster Prevention Air Corps, was involved in an accident during a hoist rescue operation in Nishiyoshino Town, Gojo City, Nara Prefecture. The helicopter had departed from the Nara Prefecture Heliport at 13:09 to rescue two individuals from a village isolated due to heavy rain from a typhoon. The crew consisted of a Pilot in Command (PIC) in the right seat, a Pilot in the left seat, a mechanic, and four rescuers (designated R1, R2, OP, and D).
Flight and Rescue Sequence
Upon arrival at the rescue site, the PIC could not find a suitable landing site and decided to conduct a hoist rescue. Rescuer B (R2) descended to the ground along with Rescuer A (R1). R2 helped the rescuee (referred to as rescuee A) put on an evacuation harness and explained precautions, including not holding onto the carabiner. The rescuee replied "OK," indicating understanding. Due to wet ground and the rescuee's stooped posture as an elderly person, R2 decided to lift her from a kneeling position. R2 attached carabiner B of his own harness to carabiner A of the rescuee's evacuation harness, per standard procedures. The hoist hook was lowered, locked, and lifting began.
Shortly after lift-off, the rescuee complained of pain. R2 immediately instructed the hoist operator (OP) to lower the hook. On the ground, R2 observed an injury to a finger on the rescuee's left hand. Lifting was then resumed, and first aid was administered inside the helicopter. An ambulance was requested to meet the helicopter at a temporary helipad in Gojo City. Rescuee A was transported to a hospital from there.
Injuries and Aircraft Damage
The rescuee sustained a serious injury to a finger of her left hand. The helicopter suffered no damage.
Rescuee's Account
The rescuee stated she had never been lifted by a helicopter before. She could not hear the rescuer's explanations due to the loud helicopter noise and her difficulty hearing. She felt intense pain during lifting, as if her finger were being torn off. She did not remember where or how she was holding on.
Rescue Equipment and Procedures
Post-accident inspection of the evacuation harness and carabiners revealed no abnormalities. The Nara Disaster Prevention Air Corps' "Operation Procedures" prescribed steps for ground rescue, including attaching the rescuer's carabiner to the rescuee's harness and confirming the hoist hook lock, but did not include confirming the rescuee's condition before lifting.
Analysis
The Japan Transport Safety Board (JTSB) analysis indicated that it is highly probable the rescuee could not hear the safety precautions due to helicopter noise and her hearing difficulty, and thus did not understand the danger of holding the carabiner. It is also highly probable that at the moment of lifting, the rescuee's finger was caught between carabiner A and carabiner B, causing injury. The rescuee's kneeling posture likely made her body prone to falling backward, leading her to hold the carabiner for support. The JTSB noted that rescuers did not notice the rescuee holding the carabiner during lift-off.
Probable Causes
The JTSB report did not provide a complete probable cause statement.