What happened
On February 5, 2019, a private helicopter flight operated by an individual pilot took off from the Lago Ranco area in Chile's Los Ríos Region. The aircraft, a Robinson R44 II (registration CC-XXX), carried two passengers on a local scenic tour. During the operation, the crew decided to land on the southwestern shore of the lake, near the beginning of the Río Bueno.
The pilot conducted a high-altitude reconnaissance flight from east to west at approximately 500 to 600 feet to assess the landing zone. Finding the area clear, the pilot initiated an approach from the northwest to the southeast. During this final phase, the helicopter’s main rotor struck medium-voltage power lines that crossed the flight path. Despite the impact, the pilot maintained control and completed the landing without further incident. Upon inspection after touchdown, it was discovered that one of the main rotor blades had sustained damage.
The investigation
DGAC Chile investigated the incident to determine causal factors and safety issues. The pilot, a 53-year-old Chilean national holding a private helicopter license with an R44 rating, reported the event on February 9, 2019. Flight logs indicated he had logged 315 hours total time in type, with 8 hours in the preceding 30 days.
The aircraft was manufactured in 2008 and was found to be airworthy prior to the flight. Maintenance records showed compliance with the manufacturer’s inspection program, with the last annual/100-hour inspection performed on January 11, 2019. Meteorological data from the Chilean Meteorological Directorate confirmed clear skies (CAVOK), good visibility, and light winds from the west during the incident window.
Findings
The investigation established that the aircraft was maintained in accordance with regulations and had no mechanical defects contributing to the event. The primary cause of the incident was the impact between the main rotor and power line cables during the landing approach.
Key contributing factors identified include:
- Obstacle Visibility: The utility poles supporting the power lines were located within dense vegetation, making them difficult for the pilot to spot from the air.
- Reconnaissance Limitations: Although the pilot performed a high-altitude reconnaissance in the opposite direction of the approach, this maneuver failed to reveal the thin cables and obscured posts. The DGAC noted that such a high pass may not be sufficient to detect low-profile obstacles like power lines hidden by foliage.
- Lack of Markings: The power lines lacked aviation warning markers or other visual aids typically used to enhance visibility for aircraft.
Safety action
DGAC Chile issued recommendations to relevant parties to disseminate the findings. Specifically, they emphasized the importance of conducting both high and low-level reconnaissance of landing areas to identify obstacles such as power lines, antennas, and trees. The authority highlighted that pilots must exercise heightened caution when operating near utility infrastructure in vegetated areas.