What happened
On October 16, 2019, a McDonnell Douglas MD 369D (registration F-GJLX), operated by Jet Systems Hélicoptères Services, was performing a combined vegetation analysis and power line inspection mission for Enedis near Blancey, France. The crew, consisting of a pilot, a system operator, and a technical observer, was conducting their third rotation of the day, inspecting high-voltage (HTA) lines.
While the pilot was maintaining a safe distance from the target line, the helicopter's fuselage struck a cable belonging to a perpendicular high-voltage (HTB) line. Simultaneously, the main rotor severed another cable from the same line. Despite the impact and resulting electrical arcs, the pilot maintained control of the aircraft and performed a precautionary landing in a nearby field adjacent to a local road.
The investigation
The investigation focused on the crew's coordination and the use of navigation tools during the mission. The BEA examined the flight data, GNSS information, and testimonies from the crew. The investigation noted that the system operator was using a software interface to monitor the lines, which included a digital map of the surrounding area.
Investigators also reviewed the pre-flight briefing and the operational procedures outlined in the operator's manual. It was noted that the aircraft was not equipped with upper or lower cable cutters, unlike other similar aircraft in the operator's fleet. The investigation also looked into the environmental conditions, specifically the visibility of the cables and the presence of metallic supports.