As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A ROUTINE INSPECTION, THE LEFT ENGINE CRANKCASE WAS FOUND CRACKED AT THE NR 4 CYLINDER MOUNTING PAD. AD 77-13-22 DOES NOT APPLY TO THIS CRANKCASE DUE TO MARKINGS. SUSPECT FATIGUE, WEAK DESIGN. SUBMITTER SUGGESTS INSPECTING AREA CLOSELY AT 100-HOUR INTERVALS. INVESTIGATE ALL OIL LEAKS IMMEDIATELY ON CONTINENTAL CRANKCASES.