What happened
On July 16, 2017, an Eurocopter AS350 B3, registration OE-XPP, operated by Everjets, was engaged in aerial firefighting operations near Alijó, Vila Chã, Portugal. During the aircraft's first mission of the day, the pilot attempted to fill a water firefighting bucket and test its release mechanism while hovering over a dam. During this low-altitude maneuver, the tail rotor made contact with the water surface, resulting in a loss of control and the subsequent destruction of the aircraft. The pilot sustained minor injuries, and there were no other occupants on board.
The investigation
The GPIAAF investigation examined the aircraft's maintenance records, the pilot's experience, and the mechanical configuration of the helicopter. The investigation confirmed that the aircraft held a valid Certificate of Airworthiness and that all components were accounted for. Analysis of the wreckage showed that the engine was producing power at the moment of impact and that all damage was consistent with the impact with the water and terrain.
Investigators identified an undocumented modification regarding the bucket release system. While the standard activation switch was located on the console, an additional switch had been installed on the collective lever. The investigation also noted that the pilot was flying this specific tail number for the first time that day, having been called in to replace an off-duty pilot, which prevented him from fully familiarizing himself with the specific cockpit configuration of this aircraft.
Findings
- The primary cause of the accident was the pilot's loss of situational awareness, which allowed the tail rotor to strike the water during the bucket testing procedure.
- The pilot lacked specific experience in firefighting operations and was not familiar with the specific bucket activation system on this aircraft.
- The aircraft featured an undocumented modification to the bucket release switch located on the collective.
- The operator had not sufficiently managed the process of introducing this specific aircraft into its active fleet and operations.
- The pilot was properly licensed, medically fit, and sufficiently rested for the flight.