What happened
On August 11, 2012, a Eurocopter AS-350-B3 helicopter, registration EC-KTU, was engaged in aerial firefighting operations to combat a brush fire in the Pregón Ravine, near Guils de Cerdanya, Spain. The aircraft was equipped with a Simplex 310 firefighting system, which included a belly tank and a suction pump suspended 3.25 meters below the right skid.
During the 23rd water drop of the mission, the crew was performing a low-altitude flyover of a steeply sloped area. Approximately two seconds after the first partial water drop, the crew heard an impact noise followed by a sudden jolt and intense vibrations throughout the aircraft. The pilot maintained control of the helicopter for approximately thirty seconds before performing a power-on emergency landing in a safe area nearby.
Upon inspection, the crew found that the suction pump hose had come to rest on the engine exhaust nozzle. The impact had caused significant damage to the aircraft, including a 32-cm crack on the tailboom and damage to two of the three main rotor blades, one of which had lost a section of material measuring 100 cm by 15 cm.