What was found
AFTER LANDING, WHILE TURNING, LT WING SAGGED. CONTINUED TAXI, LT MLG COLLAPSED. BOLT HOLDING REAR TRUNNION FRACTURED AT THE HEAD DUE TO CORROSION. ALL THE LOAD WAS TRANSFERRED TO THE FRONT TRUNNION WHICH FRACTURED AT THE END OF THE MACHINED MAIN TRUNNION STUB DUE TO OVERSTRESS, CAUSING THE RETENTION BOLT (AN4-20A) TO FAIL IN TENSION ALLOWING THE WING TO DROP OVER THE LANDING GEAR ASSY. THE GEAR STRUT PIERCED THE UPPER WING SKIN. THE BOLT HEAD REMAINED IN THE TRUNNION SLEEVE (67502-00) WHICH WAS FOUND IN THE WELL BEHIND THE REAR SPAR. THERE IS SEVERE CORROSION ON THE SHAFT OF THE BOLT FOR SEVERAL INCHES FROM THE HEAD. THE BOLT SHAFT, APPROX 1.5 INCHES FROM THE HEAD END WAS BENT AT 90 DEGREES TO THE THREAD END SHAFT APPARENTLY WHEN THE WING DROPPED OVER THE GEAR. THE RT SIDE BOLT WAS REMOVED AND HAD NO EVIDENCE OF SUCH SEVERE CORROSION. THE ANNUAL INSPECTION FOR THIS BOLT IS TO CHECK FOR THE PRESENCE OF THE HEAD. THERE IS NO REQUIREMENT TO CHECK THE TORQUE ON THE BOLT DURING THE ANNUAL INSPECTION.