What was found
(CAN) WHILE CARRYING REGULAR MAINT ON A/C, NOTICED ONE NUT WAS MISSING FROM WHEEL HUB BOLTS. UPON FURTHER INVESTIGATION, FOUND THAT BOLT HAD SHEARED AND NUT HAD FALLEN OFF, AT WHICH POINT, BOLT BACKED OUT OF HUB AND HIT BRAKE TORQUE PLATE, BENDING BOLT AND SCORING TORQUE PLATE. WHEEL AND TORQUE PLATE WERE REPLACED. BOLT HAD 173.7 HRS SINCE NEW. IT WAS REPLACED AT LAST TIRE CHANGE. STANDARD PROCEDURE IS ALL WHEEL HUB BOLTS ARE REPLACED AT TIRE CHANGE AND TORQUED IAW MFGS SPECS. THIS IS SECOND OCCURENCE OF THIS BOLT FALLING IN LAST 2 YRS. BOLT PART NUMBER IS 103-20400, BUT MAY ALSO BE RECOGNIZED UNDER AN5-40A. (X)