What was found
UPON LANDING, RT GEAR LEG, PN 7-1461-R, FAILED AT AREA OF U-BOLT ATTACH CLAMP. FAILURE RESULTED IN DAMAGE TO RT WING, PROPELLER, ENGINE AND COWLING. AIRCRAFT IS USED FOR GLIDER TOWING FROM AN UNPAVED RUNWAY AND AVERAGES 3-5 TAKEOFFS AND LANDINGS PER HOUR. TOTAL CYCLES ON GEAR LEG ARE ESTIMATED TO BE BETWEEN 15,000 TO 20,000. CRACK APPEARS TO BE FATIGUE RELATED AND IS BEING INVESTIGATED BY THE NTSB LABORATORIES. SUBMITTER RECOMMENDED A LIFE-LIMIT BE ESTABLISHED FOR THESE GEAR LEGS. TIME SINCE LAST INSPECTION IS APPROXIMATELY 170 HOURS. (X)