Approach Sequence
After completing a precision instrument landing approach (ILS), the pilot of the accident helicopter requested a clearance for another ILS approach. Prior to the outer marker, the pilot broke off the ILS approach and proceeded to execute a very high frequency omni range (VOR) approach at the departure airport. After completion of the VOR approach, the helicopter over flew the airport and departed the area to the south.
Communication and Witness Observations
Shortly thereafter, a pilot reported that he heard a radio transmission from the pilot of the helicopter that they were having "throttle linkage problems and were trying to make it back to the airport." A few minutes later, the witness heard the pilot state "they were in the pattern and for all aircraft to clear the way." No further radio transmissions were received.
Another witness, who was fishing approximately one mile east of the accident site, reported that as the helicopter flew by him in a level attitude, he heard "3 bangs," and then "the engine became silent." The witness stated that the main rotor blades were turning, and the helicopter started descending at a "slight angle." The witness lost sight of the helicopter when it descended below a tree line.
A third witness located approximately one half north of the accident site reported observing the helicopter descending through approximately 200 feet, "really fast nose first." He stated "all he could hear was the [rotor] blades like they were trying to catch air."
Examination
No structural or mechanical anomalies were observed during the examination of the helicopter.