What was found
DURING A ROUTINE INSPECTION, A RIB IN THE RIGHT WING WAS FOUND WITH A SMALL CRACK. RIB IS AFT OF MAIN WING SPAR, IS THIRD RIB OUT FROM FUSELAGE, AND IS IMMEDIATELY INBOARD OF LANDING GEAR UPPER STRUT. CRACK WAS LOCATED IN UPPER FLANGE OF RIB WHERE RUB IS RIVETED TO UPPER WING SKIN AND WAS BETWEEN RIVET HOLE AND EDGE OF MATERIAL.