What was found
AIRCRAFT IS CURRENTLY UNDERGOING A C CHECK IN THE HANGAR. WHEN CARRYING OUT NDT INSPECTION AS PER ADSI IB777570073 IN RELATION TO FAA AD 2021-13-10, A CRACK INDICATION OF APPROXIMATELY 0.6 INCHES WAS FOUND ON THE LEFT-HAND WING LOWER WING SKIN FUEL TANK #533AB CUTOUT THAT IS OUT OF REPAIRABLE LIMIT AS PER THE ADSI. SIA TECHNICAL SERVICES TEAM HAS BEEN NOTIFIED OF THE DEFECT FOR ASSISTANCE AND DISPOSITION. FINDING WAS LIKELY A FATIGUE CRACKING AS DESCRIBED IN THE RELATED FAA AD 2021-13-10.