As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) IN FLIGHT ENGINE BECAME ROUGH - POPPING/BANGING SOUND PRECAUTION AND LANDING COMPLETED ENGINE INSPECTED - CYL NR 3 HEAD FOUND BROKEN FROM BARREL. REMAINDER OF CYLS VISUALLY INSPECTED WITH NO DAMAGES FOUND. CYL NR 3 ASSY. REPLACED WITH OVERHAULED UNIT. - GROUND RUN SATISFACTORY. RERUN TO AWD 78-08-07 (VISUAL INSP.) CYLINDER FAILURE IS NOT UNHEARD OF ON THESE AIRPLANES