What was found
DURING HEAVY CHECK, RT WING STUB FITTING AT SPAR 3 RIVET REPLACEMENT HOLE HAS CRACKED. MAINTENANCE UP SIZED HOLE TO 560, IAW SB-170-57-0038. AND OVER SIZED PLUGS ARE INSTALLED IAW ETD2015-170, CONTINUATION CARDS C1-C6 FOR DETAILS. AIRCRAFT REMAINS UNTIL HEAVY CHECK IS COMPLETED.