What was found
DURING C2 + 6 YEAR (HEAVY) CHECK IN MSP, MAINTENANCE WAS ACCOMPLISHING THE EO 5331-01297-01C WORKCARD / SB BD500-530010 MODIFICATION WHEN CORROSION WAS FOUND COMMON TO THE FUSELAGE LOWER AND BOTTOM SKIN PANELS AT THE FWD CARGO DOOR CUTOUT. COMPLIED WITH ER/A 612834-14 REV A PRI REV 0, ER/A 612834-14 REV A PRI REV 1 AND ER/A 612834-14 REV A SECTION IV ASSOCIATED ER/A 00-612834 ADDED FOR AC 8305. (LP# 1631359; AIRCRAFT WAS GROUNDED)