What was found
WHILE PERFORMING A BLOCKER DOOR REPAIR, NOTICED THE INNER BARREL AT THE 6 O'CLOCK POSITION HAD A 6-INCH LONG CRACK IN THE SHAPE OF THE LETTER 'L'. CONSIDERING THE PRELOADING PROBLEM ON THE BLOCKER DOOR AND APPARENT MISALIGNMENT OF THE BLOCKER DOOR MOUNTS AT PRODUCTION, SUBMITTER STATED THIS COULD BE THE ROOT CAUSE OF THE CRACK. REPLACED T/R WITH RENTAL UNIT. FUNCTIONALLY CHECKED THRUST REVERSER AND RETURNED AIRCRAFT TO SERVICE.