As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AUS) ENGINE SUMP WORN INTERNALLY BY DIPSTICK ROD. DEPTH OF WEAR GROOVE APPROXIMATELY 0.635MM (0.025IN). THICKNESS OF SUMP SKIN 1.27MM (0.050IN). TWO OTHER SIMILAR DEFECTS FOUND FROM THE SAME OPERATOR. ALL HAVE BEEN ASSOCIATED WITH LATE MANUFACTURE RIVETED DIPSTICKS WITH SUFFIX AW OR BF. SUSPECT DESIGN PROBLEM WITH LATER MODEL DIPSTICKS.