What was found
LEFT WING, T/E, STA WS 370, OTBD OF AFT CORNER OF PANEL 551XBX, FWD OF FLAP TRANSMISSION, MAJOR CORROSION. R & R BEAM, CHORD LT WING T/E STA WS 370 IAW SRM 51-40-02. CORRODED LEVEL 2, PN 113T1407-5, SPOILERS BEAM CHORD, EXACT FS/BS LOCATION ON ACFT FROM STR, WS 273 TO 431. ACFT WAS GROUNDED.