Bell 412 Helicopter Accident in Simat de la Valldigna (EC-JCE)

Incident Overview and Flight Details On Wednesday, July 13, 2005, at approximately 08:30 local time, a Bell Helicopter Textron Bell 412, registration EC-JCE, operated by Helicópteros del Sureste, was involved in an accident in Simat de la Valldigna, Valencia. The aircraft, powered by two Pratt & Whitney PT6T-3B engines, was engaged in commercial aerial firefighting operations. The pilot, a 44-year-old commercial helicopter pilot with 2,282 total flight hours and 65 hours on the Bell 412, was the sole crew member. The aircraft had 4,958 total flight hours at the time of the accident. ## Sequence of Events The pilot began the day at 06:45 with a preflight inspection at the Siete Aguas base, departing at 07:05 for a football field in Simat de la Valldigna, which served as the fire's operational base. For the next hour and 25 minutes, the helicopter made six takeoffs and landings, transporting firefighters to the fire. After the final landing, the pilot prepared to install a helibald (water bucket) for water drops. While the rotor was at 100% revolutions and a ground technician was installing the bucket and closing the right cabin door, the helicopter began to vibrate. The pilot identified the vibrations as resonance and attempted to correct them by lifting off. As the vibrations increased, the pilot decided to make an emergency landing, during which the helicopter struck trees. The aircraft ascended approximately 3 meters and moved 15 meters forward and to the right before impact. ## Damage and Injuries The pilot and the ground technician were uninjured. The helicopter sustained significant damage, including deformation of the right skid, breaking and deformation of all main rotor blades, and the separation of the 90-degree tail rotor transmission box along with one blade and part of another. No prior maintenance issues or anomalies were reported by the pilot during the preflight check or the 85 minutes of flight prior to the accident. ## Investigation and Analysis The investigation noted that the cockpit configuration after landing did not match the flight manual, as the cyclic could move freely without resistance, and the force trim was disconnected. The system warning of cyclic displacement was inoperative because the rotor was operating above 97% revolutions. Laboratory inspection of the detached tail rotor blade fragment found no signs of prior corrosion or slow crack propagation, ruling out tail rotor failure as the original cause of the vibrations. Following the accident, the operator issued a safety circular emphasizing the importance of fully lowering the collective lever after landing and the risks of using the collective to eliminate ground vibrations.