What was found
STRINGER 21L INTERCOSTAL BETWEEN FS333.00 AND FS349.00 HAS SIGNS OF CORROSION. CORRECTIVE ACTION: REMOVED AND REPLACED INTERCOSTAL AT STRINGER 21L BETWEEN FS333.00 AND 349.00 (P/N: SH670-31823-1) IAW CRJ 700 SRM 51-25-16 TR51-0065 DATED SEP 24/2019, 51-21-11, 53-21-23, 51-42-06, 51-40-11, 51-42-21, AND 51-26-00.