What was found
DURING ANNUAL INSPECTION, A GAP BETWEEN THE ENGINE TRUSS AND FIREWALL AT THE ATTACH POINTS WAS OBSERVED. BORESCOPE INSPECTION OF THE UPPER ENGINE MOUNT ATTACH STRINGERS (P/N 0511282 & 0511282-1) BEHIND FIREWALL WERE FOUND TO BE CRACKED AT FS 0.0. AIRCRAFT HAS BEEN MODIFIED BY STC SA420CE ENGINE INSTALLATION. ENGINE INSTALLATION HAS BEEN INSTALLED FOR 14 YEARS ACCUMULATING 345 HOURS. AD 2016-14-05 AND SEB07-2 REV 2 APPLY TO SIMILAR AIRCRAFT MODEL BUT DIFFERENT SPECIFIC PARTS.