What happened
On August 8, 2015, a Eurocopter AS350 B3 helicopter, registration CS-HIA, was returning to the Arcos de Valdevez Firefighters Base after performing fire-fighting duties. The aircraft was operated by Everjets and was carrying five occupants from the National Republican Guard (GIPS) intervention corps.
During the return flight, the crew observed what appeared to be arsonists setting fire to a hillside near the village of Lugar do Côto. Following a brief discussion with the passengers, the pilot decided to deviate from the planned route to land on nearby mountainous terrain to pursue the suspected individuals. During the approach and landing maneuver, the pilot lost control of the aircraft, which struck the ground with significant force. The impact caused extensive structural damage to the helicopter, though the aircraft was destroyed. One passenger sustained minor injuries, and there were no fatalities.
The investigation
The GPIAAF investigation established that the aircraft was well-maintained, with a valid Certificate of Airworthiness, and the weight and balance were within manufacturer limits. There was no evidence of mechanical failure or system malfunction prior to the impact; the damage to the transmission system was consistent with the engine producing power at the moment of impact.
The investigation also examined the pilot's physiological state and the environmental conditions. While the pilot was properly licensed and qualified, the investigation noted that the pilot had accumulated several flight hours in a single week of intense fire-fighting operations without a scheduled lunch break. The investigation concluded that the pilot's performance was consistent with the effects of fatigue.