Incident Description
The pilot-in-command (PIC) maneuvered a Bell 212 helicopter into a 100-foot hover above a small reservoir to fill a Bambi bucket for fire-fighting operations. The rotorcraft began to settle. Perceiving that he had encountered rotor vortex conditions, the PIC slipped the helicopter to the right with the bucket still in the reservoir. This action increased the angle of the long line from the vertical or zero degree reference. Immediately thereafter, the PIC noted a loss of power in the #1 engine. He then executed a single-engine autorotation, during which a rotor blade impacted a dead tree.
Post-Crash Examination
Post-crash examination revealed that the long line had pulled aft and left from its vertical reference into the airframe structure, specifically at the 7:30 position of the hell hole in the belly of the helicopter. This resulted in: 1) the separation of one of the #1 engine push/pull rods, and 2) the deformation of engine control rods associated with the #1 engine flight idle stop (solenoid), which then sheared. The shearing of the flight idle stop caused a restriction and subsequent cessation of fuel flow to the #1 engine fuel control unit, leading to engine shutdown.