What was found
(CAN) DURING ANNUAL INSPECTION SEVERAL CRACKS WERE DETECTED AT THE RIVET HOLES WHERE THE FLAP BAY SKIN (PN 20438-2) ATTACH TO THE RIB FLANGES. CRACKS WERE STOP DRILLED AND PLATE INSTALLED OVER THE RIB FLANGE AREA IAW AIR TRACTOR INSTRUCTIONS (ATTACHED). THIS PROBLEM HAS BEEN FOUND ON EARLY SN AIRCRAFT (802-001 - 802A-0014), SUBSEQUENT S/N HAD EXTRA RIVETS INSTALLED BY MFG. THIS AIRCRAFT S/N IS 802-0121. (TC NR 20070115014)