What was found
WHILE AIRCRAFT WAS IN HEAVY CHECK MAINTENANCE FOUND THE UPPER LEFT SEAT TRACK FRAME 17 TO 19 CORRODED. MAINTENANCE REMOVED AND REPLACED THE UPPER LEFT SEAT TRACK FRAME 17 TO 19 IAW EMB 175 SRM 51-40-02, 51-41-01, AND 51-12-01. THE AIRCRAFT IS OUT OF SERVICE IN HEAVY CHECK.