Primary finding
Probable cause
The separation of the throttle cable’s outer housing from the inner housing at the throttle linkage while at a high-power setting, which prevented the pilot from being able to control the throttle and execute a proper landing flare and resulted in a hard landing.
Investigator assessment
Analysis narrative
The flight instructor of the helicopter reported that, about halfway through the flight, he "discovered that the throttle control was inoperative" and stuck in the high rpm setting. He turned the helicopter back to the departure airport and briefed his student on the situation. Upon being cleared to land, he executed a "running landing" and performed a go-around on the first try. On the second try, the skids made hard contact with the runway, and the helicopter came to a stop. A postaccident examination revealed that the helicopter had sustained substantial damage to the fuselage. The flight instructor reported that the throttle cable outer housing separated from the inner solid housing at the throttle linkage and that the internal wire could flex outside of the housing.
Source record
Factual narrative
The flight instructor of the helicopter reported that about halfway through the flight he "discovered that the throttle control was inoperative" and stuck in the high RPM setting. He turned the helicopter back to the departure airport and briefed his student on the situation. Upon being cleared to land, he executed a "running landing" and performed a go around on the first try. On the second try, the skids made hard contact with the runway and the helicopter came to a stop. A post-accident examination revealed the helicopter had sustained substantial damage to the fuselage. The flight instructor reported that the throttle cable outer housing separated from the inner solid housing at the throttle linkage, and that the internal wire could now flex outside of the housing.