What happened
On the evening of July 16, 2008, a Eurocopter AS3COB2, registration D-HAUP, was engaged in aerial firefighting operations near Ribeira de Pena, Portugal. The aircraft, operated by Helibravo Aviação, had been deployed to combat a forest fire in the vicinity of Salvador. After transporting a five-person specialized firefighting team to the site and performing seven water drops to extinguish the blaze, the pilot proceeded to pick up the crew for the return flight.
During the transition from a hover to a climb phase, the helicopter struck a medium-voltage power line, resulting in an electric strike. The impact and subsequent discharge caused light damage to one of the main rotor blades, the right-hand side windscreen, a communications antenna, and the left side of the fuselage. Despite the damage, the aircraft's flight characteristics remained stable, allowing the pilot to continue the flight to the base station approximately 1.5 NM away, where the aircraft landed safely at 19:40 UTC.
The investigation
The GPIAAF investigation focused on the circumstances surrounding the collision and the pilot's ability to identify the obstacle. The investigation established that the pilot was experienced in the area and was aware of the presence of electrical lines due to previous missions conducted that same day. Investigators also reviewed the pilot's flight and rest records, determining that there was no evidence of fatigue or accumulated stress contributing to the incident.
Findings
- The pilot maneuvered the aircraft to face the sun during the transition phase of flight.
- Because the incident occurred near sunset, the low position of the sun on the horizon limited the pilot's visual capacity to detect the power lines.
- The pilot was unable to avoid the collision once the cables became visible.
- The damage to the aircraft was limited because the power lines were medium voltage with a small cable section.
- There were no injuries to the one pilot or the five passengers on board.