What was found
FLT 6400 JFK-BNA, ON HEAVY MAINTENANCE CHECK AT BNA, FOUND AFT CABIN RIGHT SEAT TRACK HAS CORROSION BETWEEN FR 84 AND FR 85. REPAIRED BY BLENDING, DRILLING FASTENER HOLE TO 3/16". HFEC INSPECTION, FILLING BLENDED AREA, MANUFACTURE STRAP AND INSTALL AS PER EA E12-558-01.