What was found
WHILE DOING SB 977, PULLED UP BAGGAGE FLOOR, FOUND AFT STEEL STEP SUPPORT BRACKET SEVERELY CORRODED. WHEN REMOVED, FOUND STEEL SUPPORT BRACKET BROKEN AND EMPENNAGE TO FUSELAGE BULKHEAD WITH 2 FOOT CRACK IN LOWER RADIUS. SUSPECT BATTERY ACID STARTED CORROSION PROCESS. REPLACE WITH BRACKET OF DIFFERENT MATERIAL.