What was found
AFTER INSTALLING A NEW TRUNNION REQUIRED BY AD94-13-11, THE AIRCRAFT'S RIGHT GEAR COLLAPSED DURING LANDING. INVESTIGATION REVEALED THE RIGHT TRUNNION PIN AND BOLT WERE DISENGAGED FROM THE TRUNNION AND WERE LAYING INSIDE OF THE WING. THE TRUNNION PIN BOLT BARREL NUT WAS MISSING FROM THE AIRCRAFT. SUSPECTED FAILURE OF BARREL NUT CAUSED THIS INCIDENT. RECOMMEND REQUIREMENT OF REPLACING BARREL NUT WITH NEW AND SPECIFIC TORQUE REQUIREMENT BE ADDED TO AD NOTE.