What was found
(CAN) DURING AN AUDIT OF AD'S IT WAS DISCOVERED THAT AN ERROR HAD BEEN MADE BY THE OVERHAULER WHEN INTERPRETING AD96-18-14 WHICH RESULTED IN AN EXPIRED HUB BEING INSTALLED ON THE PROP. DURING OVERHAUL THE HUB AND BLADES WERE REPLACED. THE HUB SN HAD AN EXTRA DASH NUMBER ADDED BY MFG (-M3)INDICATING THAT AD95-01-02 HAD BEEN CARRIED OUT ON IT. THIS LED THE OVERHAULER TO BELIEVE THAT THIS SERIAL NUMBER WAS NOT AFFECTED BY AD96-18-14 WHICH WOULD HAVE RETIRED THE HUB FROM USE ON THIS AIRCRAFT. THE AD DID NOT CLEARLY STATE THAT THE DASH NUMBER WAS NOT A FACTOR. FURTHER CHECKING REVEALED THAT THE SAME MISINTERPRETATION HAD OCCURRED ON TWO OTHER PROPS IN THE PAST