2005 Helisul Eurocopter AS 350 B2 accident in Moimenta da Beira (F-GTHR)

Overview and flight history On 24 July 2005, a Eurocopter AS 350 B2 helicopter, registration F-GTHR, operated by Helisul and based at the Armamar heliport, was tasked with supporting wildfire suppression in the Paradinha area of Moimenta da Beira. The aircraft was equipped with a fixed ventral water tank and discharge system for firefighting operations. The pilot took off at 09:35 UTC carrying a firefighting brigade. After dropping the brigade near the fire, the helicopter searched for a water source and made its first water discharge. During the recovery maneuver, poor visibility caused by smoke led the aircraft to strike a high-voltage transmission line that had not been identified during the area reconnaissance. ## Accident sequence and damage The impact broke the power cables near the more distant pole. The cables slid along the right skid, became entangled, and acted as a tether, pulling the helicopter toward the ground. As the cables tightened, they forced the helicopter to rotate, became caught in the tail, and fractured it while dragging the aircraft down. The pilot shut down the engine and forced a landing. The helicopter crashed violently into the ground near the fire. The cabin roof was torn away and fractured, the pilot seat support broke, and one main rotor blade struck an adjacent wall and was severely damaged. The rear portion of the tail, including the vertical stabilizer and tail rotor, separated and was thrown about 12 meters from the final resting place. The power cables were ruptured, temporarily interrupting electricity to a wide region. ## Personnel, aircraft, and conditions The pilot was the sole occupant and was uninjured. The aircraft suffered severe damage, including fractures to the tail cone, damaged main rotor blades, and a fractured rotor head. The pilot was a 56-year-old Portuguese male holding a CPL(H) license, with 8,900 total flight hours and 150 hours on type. At the time of the occurrence, the sky was nearly clear, the wind was light, and the air temperature was about 27°C. The report stated that weather was not a contributing factor. The accident site was mountainous, with a pine forest on a slope south of Castelo, and the helicopter came down in an abandoned agricultural field near the fire at about 2,250 feet altitude.