Accident Overview
A helicopter conducting a medivac flight crashed after the pilot reported a control issue. Shortly after departing from a hospital, the pilot contacted company dispatch and requested that a mechanic meet him at a nearby airport due to "binding in the right pedal." The helicopter subsequently impacted terrain following a loss of control.
Witness Accounts
An airport employee saw the helicopter hovering over the ramp and believed it was preparing to land. Four other witnesses reported seeing the helicopter climbing and thought it was taking off. Multiple witnesses observed the helicopter spinning prior to its descent, though the direction of rotation varied among accounts. One witness stated that the helicopter's nose remained stationary facing east while the tail swung back and forth. This witness then saw the helicopter veer left and lost sight of it behind buildings. Another witness described the helicopter rocking nose-to-tail and moving in a circle without spinning before impact.
Mechanical Findings
Post-accident examination of the helicopter revealed that one of the scuff sleeves on the tail rotor pitch change rod had shifted approximately 3 inches aft of the bearing bracket. The top of the sleeve was gouged and scuffed, and both ends were slightly curled away from the rod. The forward edge of the sleeve was torn. No other mechanical failures or malfunctions of the engine, airframe, or systems were identified that would have resulted in the accident. The guarded hydraulic cut-off switch was found in the off position.
Pilot Information and Conditions
The pilot had accumulated approximately 2,500 hours of helicopter flight time, with 43.8 hours in the specific make and model of the accident helicopter. At the time of the accident, wind was from 200 degrees at 16 knots, gusting to 21 knots. The Federal Aviation Administration Rotorcraft Flying Handbook states that loss of tail rotor effectiveness can occur in all single-rotor helicopters at airspeeds below 30 knots, often due to certain wind directions while hovering or insufficient tail rotor thrust for a given power setting at high altitudes.