As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) UPON REMOVAL OF BELL INSTALLED HEATER ASSY. A VISUAL INSPECTION WAS COMPLETED OF THE AREA`S SURROUNDING STRUCTURE. THE LT AFT FRAME ASSY WAS FOUND CRACKED BEYOND LIMITS. THE CRACK WAS NOTED TO PROTRUDE FROM A RIVET HOLE ACROSS THE FACE OF THE FRAME. FRAME ASSY WAS REMOVED AND REPLACED NEW.