What happened
On October 15, 2018, a Robinson R44 helicopter, registration LV-BSB, departed from Aeropuerto Héroes de Malvinas in Tandil for a recreational flight toward Pilar. Approximately ninety minutes into the flight, the aircraft struck medium-voltage power lines crossing National Route 3 near Gorchs. The impact caused the pilot to lose control, leading to a subsequent crash into the ground. The aircraft was destroyed in the accident, which occurred during daylight hours under favorable weather conditions. The pilot and three passengers were evacuated from the wreckage and transported to local hospitals with 4 serious injuries.
The investigation
The investigation examined the wreckage and the flight path to determine the cause of the impact. Investigators found physical evidence on one of the main rotor blades consistent with contact with electrical wiring. The power lines involved were positioned approximately 15 meters above the ground. While the aircraft's Emergency Locator Transmitter (ELT) was set to the armed position, its antenna was disconnected, which prevented the transmission of a distress signal to the Argentine Mission Control Center.
Analysis of the flight path revealed that the approach angle made the wires difficult to identify. Furthermore, one of the supporting utility towers was obscured by a grove of trees, hindering visibility of the hazard. Regarding occupant safety, while the pilot stated all passengers were buckled, the nature of the injuries suggested that only the occupants in the rear seats were actually wearing seatbelaries at the time of impact.
Findings
- The pilot initiated a descent to land due to physiological needs.
- The primary cause of the accident was the impact with medium-voltage power lines.
- Obstruction of visibility was contributed to by a utility tower being hidden behind trees.
- The lack of an effective distress signal was due to the ELT antenna being disconnected from the unit.
- Evidence indicates that only the passengers in the rear of the aircraft were secured with seatbelts during the collision.