What happened
On 5 August 2017, a Bell 206B3 helicopter, registration D-HHMP, was performing agricultural spraying operations near Pego, Alicante. The aircraft, operated by Rotorsun, was engaged in the application of phytosanitary products over a rice paddy field. During the sixth takeoff of the day, the aircraft entered the initial climb phase but failed to reach effective translational lift speed.
As the helicopter climbed, it began to lose altitude. The right side of the spray boom made contact with the crop field, triggering a dynamic rollover. The aircraft pivoted on the boom and the right skid before the main rotor impacted the ground. The pilot was able to exit the aircraft under his own power and sustained no injuries, though the aircraft suffered significant damage to its landing gear, spray booms, engine compartment, and main rotor.
The investigation
The CIAIAC investigation examined the flight path data from the aircraft's DGPS guidance system, the pilot's training and experience, and the operator's safety protocols. Investigators analyzed the engine torque levels during the takeoff and reviewed the pilot's recent flight schedule. The investigation also reviewed the operator's manual, which outlines specific risk mitigation measures for pilots with limited experience in specialized aerial spraying tasks.
Findings
- The pilot was properly qualified and physically fit, but was categorized by the operator as having "little experience" in the specific activity of aerial spraying.
- The aircraft was operating within its weight and center of gravity limits.
- The pilot applied insufficient power during takeoff, estimated at 90% engine torque, whereas approximately 95% was required to prevent altitude loss before reaching translational lift.
- The pilot executed a curved flight path rather than a straight path during the takeoff maneuver.
- The operator's established mitigation measure—limiting flight periods to reduce fatigue and workload for inexperienced pilots—was improperly implemented for this specific operation.