What happened
The pilot was conducting agricultural spraying operations on a field at an altitude of approximately 10 feet above ground level (agl). The flight path ran parallel to a set of telephone lines. During this low-level operation, the helicopter's main rotor blades made contact with the overhead utility wires. This impact caused the aircraft to lose lift and descend rapidly into the terrain.
Upon impact with the ground, the helicopter's skids became embedded in a row of irrigation pipes. The force of the collision caused the aircraft to pitch forward violently. The helicopter subsequently nosed over and came to rest in an inverted position on the ground.
The investigation
Following the accident, the pilot was interviewed regarding the condition of the aircraft prior to the event. The pilot reported that there were no known mechanical malfunctions or failures with the helicopter before the collision occurred. The investigation focused on the sequence of events leading to the loss of control and the subsequent impact.
Findings
The primary factor in this accident was the proximity of the main rotor blades to the telephone lines during low-altitude flight. The lack of sufficient clearance between the rotating blades and the overhead utility infrastructure resulted in the strike. The pilot's decision to fly parallel to the lines at such a low altitude contributed directly to the collision.