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 REPORTED THE FLOORBEAM UNDER PLASTIC WATER DRAIN TRAY ASSY AT FS X370.00 HAS ELONGATED HOLES. MAINTENANCE PERFORMED A MAJOR REPAIR ON FLOORBEAM AT FS X370.00 IAW BOMBARDIER EO DHC-8-400-53-L01678, MATERIAL FABRICATED FROM 0.040 AL 2024-T3 & 0.063 AL 7075-T6. AIRCRAFT IS CURRENTLY STILL OUT OF SERVICE FOR HEAVY CHECK.