Flight Details
On 15 October 2018, a Robinson R44 helicopter registered as LV-BSB departed from Aeropuerto Héroes de Malvinas in Tandil, Buenos Aires, at 19:30 UTC. The flight was a recreational trip destined for Estancia Las Chacritas in Pilar, Buenos Aires. After approximately 1 hour and 30 minutes of flight, the helicopter struck a medium-voltage power line that crosses National Route 3. The pilot lost control of the aircraft, which then impacted the ground. The accident occurred during daylight hours in good weather conditions.
Investigation Findings
The investigation did not identify anomalies in the helicopter's systems or controls. Damage marks on the main rotor blades indicated contact with the power line, which was approximately 15 meters above ground. The helicopter came to rest on waterlogged terrain at a 90-degree lateral inclination, 140 meters from the power line. The Emergency Locator Transmitter (ELT) was found with its arming switch in the 'armed' position, but the antenna connection was disconnected. No ELT signals were detected by the Argentine Mission Control Centre. The pilot stated that he had decided to land due to physiological needs and that although he noticed other power lines, he did not see the one crossing the road. All occupants reported wearing seat belts; however, the degree of destruction prevented verification of belt use. Injuries indicated that only the rear passengers were likely using restraints at impact.
Analysis and Conclusions
The analysis concluded that the damage to the helicopter resulted from the ground impact, with the rotor blade marks from the power line strike. The ELT antenna disconnection was likely caused by the impact. According to Argentine Civil Aviation Regulations Part 154, overhead power lines crossing roads must be marked if they pose a safety risk. However, the line crossing Route 3 was not considered a hazard for aircraft due to its distance from any aerodrome. The helicopter's flight path prior to impact made the transverse power line difficult to identify. One of the support towers was located behind a grove of trees.
The investigation identified the following factors related to the accident: the pilot decided to land due to physiological needs; the aircraft struck a power line and crashed; one of the power line support towers was positioned behind trees, reducing visibility. The helicopter was destroyed.