What was found
PASSENGER CABIN BENEATH FLOORBOARD 226CRF, FORWARD LEFT HAND CORNER AT FRAME18, NEXT TO RIGHT HAND SEAT TRACK, FLOOR SUPPORT STRUCTURE HAS SURFACE CORROSION. FOUND TO BE OUT OF LIMITS PER SRM 51-75-16. MAINTENANCE REMOVED AND REPLACED FLOORBEAM IAW SRM 51-41-02,51-43-03, AND 51-43-04.