The detachment of the cyclic-stick of the helicopter was due to fracturing of the cast Mg-alloy socket. The socket had failed by static overload. Evidences suggest that the cyclic-stick had experienced sudden impact load in a direction away from the pilot leading to the failure of the socket. There were no evidences of progressive failure such as fatigue. Also, no metallurgical or mechanical abnormalities were responsible for the failure. A detailed analysis of the failure is presented in this report.