What was found
WHILE AIRCRAFT WAS IN HEAVY CHECK MAINTENANCE FOUND THE FORWARD CARGO DOOR LOWER SILL BEAM CORRODED. MAINTENANCE REMOVED AND REPLACED THE FORWARD CARGO DOOR LOWER SILL BEAM IAW EMB 170 SRM 51-40-02, 51-23-06, 51-43-01, 51-43-02, AND 51-41-01. "MAJOR REPAIR" THE AIRCRAFT IS OUT OF SERVICE IN HEAVY CHECK.