What was found
THE PURPOSE OF THIS EO IS TO DOCUMENT A MAJOR REPAIR. DURING ROUTINE INSPECTION A-CHECK, MX FOUND THE NR 3 RT THRUST REVERSER CORE COWL WITH A 4.0 INCH CRACK LOCATED APPROX AT THE 1 O'CLOCK POSITION (REF FIG1). OBTAIN ACCESS TO THE NR 3 RT THRUST REVERSER CORE COWL. STOP DRILL THE ENDS OF THE CRACK. PROTECT THE DAMAGED AREAS BY FILLING THE AREAS OF DAMAGE WITH BMS5-25 SEALANT OR EQUIVALENT TO CONTOUR AND APPLY 2 LAYERS OF ALUMINUM FOIL TAPE (SPEED TAPE) EXTENDING MINIMUM 2 INCHES OF THE SURROUNDING DAMAGED AREA ON ALL SIDES TO RESTORE SURFACE CONTOUR AND PREVENT MOISTURE/AIR INGRESS. CONTACT MX CONTROL AND OPEN A NON MEL TO TRACK PART 2 REPEAT INSP REQUIREMENTS.