What was found
DURING REPLACEMENT OF THE RT ENGINE NR 3 EXHAUST RISER, THE TECH REMOVED THE AFT MUFFLER. NOTED THE MUFFLER HAD A LARGE, FOUR INCH CRACK. THE CRACK WAS NOT VISIBLE UNLESS THE MUFFLER IS REMOVED, BECAUSE THE FORWARD MUFFLER BLOCKS THE VIEW OF THE AFT MUFFLER'S FRONT SIDE.