What happened
On August 27, 2015, a WSK PZL-M18B, registration EC-FBJ, was engaged in aerial firefighting operations near Castro Caldelas, Ourense. The aircraft, operated by Servicios Aéreos y Tratamientos Agrícolas S.L. (SAETA), was part of a formation responding to a forest fire.
Following takeoff from the Doade base, the aircraft flew in formation behind a lead unit. During the flight, the pilot attempted a turn to avoid colliding with a mountain. During this maneuver, the aircraft banked at an angle of nearly 90 degrees, at which point the pilot executed a water drop. Shortly after, the aircraft entered a nearly vertical, inverted descent and struck the side of a mountain. Despite the high-energy impact and the destruction of the aircraft, the pilot survived with serious injuries and was able to exit the wreckage under his own power.
The investigation
The CIAIAC investigation examined the flight sequence, the aircraft's condition, and the pilot's training. Investigators analyzed eyewitness photographs taken moments before the impact, which showed the aircraft in a steep bank and then in an inverted, vertical trajectory.
The investigation established that the aircraft was flying at a lower altitude and slower speed than the lead aircraft in the formation. This discrepancy was attributed to the hasty takeoff required by the formation flying, which shortened the climb phase on the runway heading. The investigation also reviewed the pilot's experience, noting that while he was a highly experienced commercial pilot, he had only been flying this specific aircraft type for ten days and had primarily been performing coordination and observation roles rather than water-dropping missions.
Findings
- The pilot lost control of EC-FBJ due to a stall occurring during a low-altitude turn to avoid terrain.
- The pilot's limited experience with the specific characteristics of the WSK PZL-M18B contributed to an inability to maintain necessary speeds and assess maneuvering limits.
- Flying in formation led to incomplete pre-flight planning and a hasty takeoff that prevented the aircraft from reaching the same altitude as the lead plane.
- The pilot delayed the decision to remedy altitude deficiencies, potentially due to the pressure to maintain formation and reach the fire site.
- Environmental factors, including a likely tailwind and turbulence, reduced the margin for error during the maneuver.