What was found
WHILE AIRCRAFT WAS IN FOR HEAVY CHECK, MAINTENANCE REPORTED LEVEL 2 CORROSION ON THE LT I/B SEAT TRACK AT FRAME 78. MAINTENANCE REMOVED AND REPLACED THE LT I/B SEAT TRACK AT FRAME 78 IAW SRM 51-43-04, 51-43-03, 51-41-01, 51-40-02 & 51-40-03. AIRCRAFT IS CURRENTLY STILL OUT OF SERVICE FOR HEAVY CHECK COMPLETION.