What was found
AREAS OF STRINGER MATERIAL WITHIN ACFT CTR AND OTBD WING FOUND TO BE SUFFERING FROM MILD EXFOLIATION CORROSION. CORROSION MANIFESTED ITSELF AS A LOCALIZED BUMP OR BULGE WITHIN THE VERTICAL LEG OF THE STRINGER MATERIAL. ALL STRINGER MATERIAL SUFFERING FROM THIS CONDITION WAS LOCATED ON THE UNDER SIDE OF THE UPPER WING SKIN WITHIN THE WING FLAP BAYS. GRIPPING THE VERTICAL LEG OF THE STRINGER MATERIAL BETWEEN FINGER AND THUMB AND RUNNING DOWN BETWEEN WING RIBS REVEALED THE AREAS OF DETERIORATION. OUR RECOMMENDATION IS TO INCORPORATE A SPECIFIC INSP OF THIS STRUCTURE INTO THE ACFTS ESTABLISHED MM OR INSP. (K)