What was found
UPON RETURN FROM A TRAINING FLIGHT A LARGE QUANTITY OF OIL WAS FOUND IN THE ENGINE COWL AND ON THE GROUND UNDER THE AIRCRAFT. AFTER WASHING THE ENGINE DOWN, AND AN ENGINE RUN, IT WAS DETERMINED THAT THE OIL WAS COMING FROM THE AIR CONDITIONING DRIVE SHAFT SEAL IN THE STARTER ADAPTER ASSEMBLY. FURTHER DISASSEMBLY AND INSPECTION REVELED THAT THE BALL BEARING, JUST BEHIND THE SEAL, HAD COME APART. NO METAL WAS FOUND IN THE OIL FILTER OR THE STRAINED ENGINE OIL. INSPECT SEAL AT PREFLIGHT TO DETECT EXCESSIVE LEAKAGE.