As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AIRCRAFT WAS IN FOR HEAVY CHECK, MAINTENANCE FOUND LEVEL 2 CORROSION ON RIGHT OUTBOARD SEAT RAIL BETWEEN FUSELAGE STATION X-237.6 AND X-592.0 IN 19 DIFFERENT LOCATIONS. MAINTENANCE REMOVED AND REPLACED THE SEAT RAIL BETWEEN FUSELAGE STATION X-237.6 AND X-592.0 IAW BOMBARDIER Q400 SRM 51-42-05, 51-40-10 AND 51-40-15. AIRCRAFT IS CURRENTLY STILL OUT OF SERVICE FOR HEAVY CHECK COMPLETION.