What happened
On May 20, 2015, an AS-350 B2 helicopter, registration PR-POL, was conducting a police support operation in the rural area of Ibateguara, Alagoas. The aircraft, operated by the State Secretariat of Social Defense of Alagoas, had departed from Maceió to assist local law enforcement.
During the mission, the crew performed a hover and subsequently initiated a go-around maneuver between two hills. During this maneuver, the aircraft struck a low-voltage rural electrification cable. The impact caused the cable to break and become entangled in the main rotor components. The pilot managed to perform an emergency landing a few meters from the collision site. After the aircraft came to a halt, the crew removed a piece of the electrical cable wrapped around the main rotor base. Following a visual inspection, the crew successfully returned the aircraft to Maceió. All four occupants were uninjured, though the aircraft sustained light damage to the main rotor pitch links, tail rotor blade, engine exhaust, horizontal stabilizer, instrument panel, and VHF antenna.
The investigation
CENIPA's investigation focused on the circumstances leading to the wire strike. Investigators examined the flight history, the crew's experience, and the organizational management of the Air Operations Group (GOA). The investigation noted that the aircraft was within weight and balance limits and had a valid airworthiness certificate. However, the investigation revealed that while the pilot held a valid medical certificate, the other three crew members were flying with expired medical certificates.
Technical analysis of the impact showed that the terrain, a valley situated between two elevations, contributed to the difficulty in spotting the unlit wires. Furthermore, the investigation looked into the lack of coordination between the flight crew and the ground teams, as well as the absence of approved operational manuals (MGSO) and standardized Crew Resource Management (CRM) training within the organization.