What happened
On January 18, 2008, at approximately 16:30 local time, a private Robinson R-44 helicopter, registration EC-HSN, was conducting a VFR flight from Madrid Cuatro Vientos Airport toward the Lozoya Valley. The flight was carrying a pilot and one passenger.
While cruising at approximately 8,000 ft over the Cabeza de Hierro Mayor peak in the Sierra de Guadarrama, the pilot observed smoke and smelled burning inside the cabin. In response, the pilot attempted an emergency landing on the mountain summit. The aircraft made initial contact with the snow-covered terrain at 2,365 ft, but due to excessive forward speed and a tailwind, the helicopter slid 95 meters down the slope. During the slide, the landing skids collapsed, causing the fuselage to tilt and a rotor blade to strike a rock. Immediately following the impact, a fire broke out, which ultimately consumed the majority of the aircraft.
The two occupants managed to evacuate the cabin through the right door. Although they initially attempted to suppress the flames, they were forced to abandon the effort to avoid an explosion. The occupants eventually reached safety after walking for two and a half hours to the Valdesquí mountain station.
The investigation
The investigation focused on the sequence of the emergency landing and the circumstances leading to the aircraft's destruction. Investigators examined the terrain, which was covered in 40 cm of snow, and the flight parameters at the time of the incident. The investigation also reviewed the pilot's experience, noting that while the pilot held a PPL(H) and had significant time in the R-41 type, they lacked specialized mountain flying training.
Technicians examined the wreckage, finding that the engine, accessories, and cockpit instruments were almost entirely incinerated. Because of the intensity of the fire, investigators were unable to determine the original source of the smoke reported by the pilot or identify any electrical malfunctions.