What happened
On October 26, 2017, at approximately 19:15 local time, a Robinson R44 helicopter, which bore no visible registration, crashed in the municipality of Villablanca, Huelva. Witnesses observed the white aircraft flying at a very low altitude, approximately 20 meters above the terrain, traveling in a southwest direction. Shortly after the aircraft disappeared from view, witnesses heard a loud explosion followed by a large column of black smoke.
The aircraft's impact sequence began with the tail boom striking the ground, which led to the airframe overturning onto its right side. During this process, the main rotor blades struck the terrain with high energy. The subsequent rupture of the fuel tanks caused an intense fire that consumed nearly the entire airframe and burned for approximately 40 minutes. The pilot, who was the sole occupant, survived the initial impact but died due to exposure to the fire.
The investigation
Investigators examined the wreckage and the flight dynamics to reconstruct the final moments of the flight. The investigation established that the aircraft was flying at low speed and low altitude over undulating terrain. Analysis of the wreckage, including the deformation of the tail cone and the main rotor mast, indicated that the aircraft was in a nose-up attitude at the moment of impact.
Investigators also evaluated the environmental conditions. At the time of the accident, the sun was at a low elevation and azimuth that placed it directly in front of the aircraft's flight path. Furthermore, while the pilot had previously attended theoretical flight training, records from the Spanish Aviation Safety Agency (AESA) confirmed that the pilot did not hold a valid flight license at the time of the accident.
Findings
- The loss of control at low altitude during an abrupt approach or rapid braking maneuver was the most probable cause of the accident.
- The pilot's loss of visual references to the ground, caused by sun glare due to the sun's position and the aircraft's attitude, acted as a contributing factor.
- The aircraft struck the ground with its tail skid and stabilizers first, leading to a loss of anti-torque control and subsequent destabilization.
- There were no indications of engine or transmission failure prior to the impact.