What was found
TOOL MARK COMMON TO FLOOR STRUCTURE WEB AT FS364.00+8 AND LBL28 ***AIRCRAFT REMOVED FROM SERVICE*** REMOVED TOOL MARK ON FLOOR STRUCTURE WEB AT FS364.00+8 AND LBL28 WITH BLEND DIMENSIONS OF 0.600Ï¿½L X 0.500Ï¿½W X 0.027Ï¿½D WITH A REMAINING THICKNESS OR 0.023Ï¿½ FROM THE ORIGINAL THICKNESS OF 0.050Ï¿½. BLEND FOUND OUT OF LIMITS, REF CRJ SRM 53-00-00 REV 38. REMOVED FLOOR BEAM FROM FS364.00 TO FS379.00 LBL28. DISCOVERED 3 ADDITIONAL TOOL MARKS AFTER REMOVAL OF FLOOR BEAM, 1) 0.3Ï¿½L X 0.1Ï¿½W X 0.001Ï¿½D, 2) 0.3 Ï¿½L X 0.2Ï¿½W X 0.001Ï¿½D, 3) 0.7Ï¿½L X 0.4Ï¿½W X 0.004Ï¿½ D. BLENDED ALL TOOL MARKS TO A SMOOTH CONTOUR, HFEC PERFORMED AT ALL BLENDED AREAS WITH NO INDICATIONS. REPAIRED FLOOR STRUCTURE FROM FS364.00 TO FS379.00 AND REINSTALLED REF MHI REO 601R-53-21-3427 REV Ï¿½ DATED 2021-04-03.