What was found
R/H FLOOR SILL AT FS 559+88, FS 559+101.75, AND FS 600 AT RBL 41 AROUND NUT PLATE HOLES HAVE CORROSION. FAA IDENTIFIED DURING AGING AIRCRAFT INSPECTION. ***AIRCRAFT REMOVED FROM SERVICE*** REMOVED CORROSION AT 4 EACH AREAS RBL 41: FS 559+88 (P1)= 1.4"L X 1"W X .030"D; FS 559+ 93.5 (P2) = 1.4"L X 1"W X .063"D; FS 559+101.75 (P3)= 1.2"L X .950" X .025"D; FS 600 (P4) = .800"L X .700"W X .004"D. AREAS P1 P2 AND P3 ARE NOT WITHIN ALLOWABLE LIMITS IAW CRJ200 SRM 53-00-00 REV 38. AREA P4 IS WITHIN ALLOWABLE LIMITS IAW CRJ200 SRM 53-00-00 REV 38. REMOVED FLOOR SILL AT FS 559 TO 559+112 RBL 41 IAW CRJ200 SRM 51-42-06 REV 38 AND 51-42-20 REV 38. FABRICATED FLOOR SILL REPLACEMENT OUT OF 7075-T6 .063" IAW CRJ200 SRM 53-51-43 REV 38. INSTALLED REPLACEMENT FLOOR SILL AT FS 559 TO FS 559+112 AT RBL 41 IAW CRJ200 SRM 51-42-06 REV 38 AND 51-42-20 REV 38. HFEC PERFORMED WITH NO INDICATIONS. RESTORED PROTECTIVE FINISH. WORK PERFORMED AT AERSALE CRS4AER685B ON W/O #03375 CARD #50008 TT:39,614 TC37,971