As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING INSPECTION FIREWALL WAS FOUND CRACKED BETWEEN LOWER RIGHT ENGINE MOUNT ATTACH POINT AND COWLING FLANGE. CRACK WAS 2.50 INCHES LONG AND RAN HORIZONTALLY. SUBMITTER SPECULATES CAUSE WAS AGE OF PART. RECOMMEND CLOSE AND DETAILED INSPECTION OF THIS AREA OF THE FIREWALL ON REGULAR BASIS. (X)