What was found
DURING 100 HR INSPECTION THE FORWARD SPINNER BULKHEAD WAS FOUND TO BE CRACKED AROUND ALL SIX (6) BOLT HOLES. THINK THAT THE CAUSE OF THE PROBLEM IS THAT WHEN THE PROP MOUNTING BOLTS ARE TORQUED TO THE LIMITS GIVEN IN THE SRM AND THAT THE FORWARD BULKHEAD GETS PULLED DOWN SLIGHTLY INTO THE CHAMFER OF THE PROP BOLT HOLES AND THIS IN TURN STRESSES THE PART LEADING TO CRACKING. TO SOLVE THIS PROBLEM, THINK THAT THE TORQUE OF THE MOUNTING BOLTS AND THE DESIGN OF THE BULKHEAD NEED TO BE EVALUATED AND CHANGES MADE. ANOTHER SOLUTION MIGHT BE TO ADD A PLATE OVER THE MOUNTING AREA MUCH LIKE THE ONE REQUIRED FOR SOME 152 PROP INSTALLATIONS TO ALLOW THE STRESS FROM THE MOUNTING BOLTS TO BE MORE EVENLY DISTRIBUTED. (K)