What was found
LEFT WING LE CORROSION ON RIB AT LES 436. REMOVED LT WING TAI DUCT, CORROSION OUT OF LIMITS ON RIB. R & R RIB IAW SRM 51-40-02 PARA 7 & 4B. REINSTALLED TAI DUCT IAW MM 20-11-00, LEAK CHECKED GOOD IAW MM 3071-00. CORRODED LEVEL 2, PN 114T2200-17, PART NAME RIB, SN N/A, FS & BS LT WING LE. ACFT WAS GNDED.