What was found
TCAS ANTENNA SKIN HAS CORROSION AT FS 295+4. AIRCRAFT REMOVED FROM SERVICE. REMOVED CORROSION ON FUSELAGE SKIN UNDER TCAS ANTENNA IN 4 EA LOCATIONS (P1) FS 295 +4 STR 0+1.165 (P2) FS 295+4 STR 0-1.765 (P3) FS 295+10.394 AND STR 0+1.394 438?L X .08?W (P4) FS 295 +10.394 AND STR 0 1.394 .634L X 0.6?W, REF CRJ 200 SRM 51-21-06, REV 38. PERFORMED HFEC INSPECTION ON FUSELAGE SKIN BENEATH UPPER TCAS ANTENNA AT 4EA LOCATIONS (P1) FS 295 +4 STR 0+1.165 (P2) FS 295+4 STR 0-1.765 (P3) FS 295+10.394 AND STR 0+1.394 438?L X .08?W (P4) FS 295 +10.394 AND STR 0 1.394 .634?L X 0.6?W, REF CRJ 200 NDTM PART 1 REV 41 51-20-06, NO INDICATIONS NOTED. EDDY-CURRENT TESTER S/N 200051301 CAL DUE: 01/24/21. PERFORMED UT THICKNESS INSPECTION ON FUSELAGE SKIN BENEATH UPPER TCAS ANTENNA AT 4EA LOCATIONS. (P1) FS 295 +4 STR 0+1.165 (P2) FS 295+4 STR 0-1.765 (P3) FS 295+10.394 AND STR 0+1.394 438?L X .08?W (P4) FS 295 +10.394 AND STR 0 1.394 .634?L X 0.6?W. (P1) THICKNESS .050", (P2) THICKNESS .054", (P3) THICKNESS .053" AND (P4) THICKNESS .051" WITHIN LIMITS, REF AWAC SUPPLEMENT NO: 16-122B REV-B DATED: 10/24/2017 AND CRJ 200 NDTM PART 4 REV 41 51-00-001. UT THICKNESS GAUGE S/N 151136107 CAL DUE: 09/16/2021.