What was found
AFTER GROUND RUN AND HOVER TO CHECK ENGINE PERFORMANCE, AIRCRAFT WAS LANDED AND COLLECTIVE WAS LOWERED TO SECURE FRICTION. MODERATE PRESSURE WAS APPLIED AND BEFORE FRICTION COULD BE SET, A BANG WAS HEARD. THE PILOT'S COLLECTIVE STICK DROPPED APPROXIMATELY 1 INCH. FURTHER INSPECTION, FOUND PILOT'S COLLECTIVE SOCKET HAD CRACKED ON AFT SIDE ABOVE BOLTS SECURING TO TORQUE TUBE.