What happened
On August 3, 2006, at approximately 15:00 local time, an Agusta Bell AB-412 helicopter, registration D-HAFV, was performing firefighting operations near Coín, Málaga. The aircraft, operated by FAASA, landed on a slope to disembark a firefighting brigade. After the crew members exited, they began deploying a "Bambi Bucket" water bucket on the ground.
During this deployment, the helicopter became unstable. The pilot attempted to climb to avoid potential overturning, but the aircraft began dragging the bucket, which caused the helicopter to drift backward. Unable to regain control, the pilot attempted an autorotation landing on an adjacent area, but the aircraft struck the ground with significant force. The pilot sustained serious injuries, including spinal fractures and facial trauma, while the other crew members were uninjured. The aircraft sustained major damage, including a broken landing gear and a displaced main transmission.
The investigation
The CIAIAC investigation focused on the landing conditions, the aircraft's configuration, and the coordination between the flight crew and the ground brigade. Investigators examined the terrain, which consisted of two platforms separated by a 50 cm height difference. The uniform color of the ground likely obscured the uneven surface, leading the pilot to land with only the front of the skids supported.
Technical inspections revealed that several critical systems were not configured according to standard operating procedures. Specifically, the force trim and AFCS systems were disconnected, and the CARGO REL switch was in the "OFF" position, which prevented the pilot from using the electrical release for the bucket. Furthermore, the investigation noted that the movement of the bucket during the attempted takeoff likely induced oscillations in the aircraft's center of gravity, further complicating stabilization.
Findings
- The helicopter landed on uneven terrain, with only the front portion of the skids making stable contact with the ground.
- The pilot failed to follow post-landing procedures, leaving the force trim and AFCS systems deactivated.
- The CARGO REL switch was in the OFF position, preventing an immediate electrical release of the bucket during the emergency.
- There was a lack of formal coordination procedures between the flight crew and the firefighting brigade, meaning ground personnel did not provide vital information regarding skid stability or obstacles.
- The sudden movement of the suspended water bucket likely caused center-of-gravity shifts that prevented the pilot from stabilizing the aircraft.
Safety action
- REC 01/10: It is recommended that AESA require operators of aircraft used for transporting firefighting crews to establish coordination procedures with the organizations responsible for those crews. These procedures should enable ground personnel to support pilots during landings on unprepared terrain by providing information on obstacles and skid support.