What was found
NR 1 PYLON AFT SPHERICAL BEARING SUPPORT BULKHEAD, YN 417.212, HAS A 10 INCH CRACK AT INBOARD INSIDE RADIUS. CRACK WAS DISCOVERED BY AN INSPECTOR WHILE PERFORMING THE SB 54-74 INSPECTION. THE NR 3 PYLON WAS ALSO INSPECTED AND NO CRACKING WAS EVIDENT. CRACK APPEARS TO HAVE ORIGINATED AT ZN 55.692 AND PROPAGATED DOWNWARDS TO ZN 44.705. REMOVED AND REPLACED THE BULKHEAD PER EA 8-5410-20129. (NOTE: THIS IS THE FINAL C/A).