What was found
WHILE C/W SB 70-048-57, 2 CRACKS WERE FOUND. ONE IN THE LOWER WEB OF THE LT FLAP INBOARD CARRIAGE, ONE INCH FROM THE AFT ROLLER STUD, AND THE OTHER IN THE VERTICAL WEB, .3750 INCH FROM THE FORWARD ROLLER STUD. BOTH CRACKS WERE BEYOND ALLOWABLE STOP DRILL LIMITS IAW THIS SB. PART WAS CHANGED WITH NEW P/N WHICH HAS BEEN MODIFIED WITH THICKER WEBS. SUBMITTER SUGGESTS OPERATORS WHO HAVE NOT C/W THIS SB SHOULD DO SO BEFORE FURTHER FLIGHTS.