Incident Details
During a training flight, the flight instructor noticed that the throttle control had become inoperative and was stuck in the high RPM setting approximately halfway through the flight. Realizing the issue, he turned the helicopter back toward the departure airport. He briefed his student on the situation to ensure awareness.
Response
After being cleared to land by air traffic control, the instructor executed a running landing approach. On the first attempt, he performed a go-around. On the second attempt, the helicopter's skids made hard contact with the runway surface, and the helicopter came to a stop.
Post-Accident Findings
A post-accident examination revealed that the helicopter had sustained substantial damage to the fuselage. Investigation showed that the throttle cable's outer housing had separated from the inner solid housing at the throttle linkage. This separation allowed the internal wire to flex outside the housing, rendering the throttle control inoperative.