As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AFTER LANDING, A POST-FLIGHT INSPECTION REVEALED AN OIL LEAK IN THE NR1 PROP. FURTHER INVESTIGATION SHOWED THAT THE BLADE SHIMS HAD BEEN INSTALLED ON THE WRONG SIDE OF THE BLADE RETAINING RING. THE SHIMS HAD BROKEN AND DAMAGED THE OIL SEALS. THE OTHER 3 PROPS WERE CHECKED AND THE SAME PROBLEM WAS FOUND ALONG WITH MORE DAMAGED SEALS. (TC NR 20061205006)