What was found
MAJOR REPAIR REF TASK CARD 59745401C ACCOMPLISH DOUBLER REPAIR AT LOWER FUSELAGE STA 1393 PER ITEM 2A. SKIN REPAIR BS 1385-1401 BETWEEN STR 28 LT-STR 29 RT AS STAGE 2 PER FAA FORM 8100-9. MAJOR REPAIR ACCOMPLISHED. INSTALLED EXTERNAL DOUBLER REPAIR AT STA 1393 STR 28L-24R IAW ECRA5360-01265. THRESHOLD TO BEGIN SUPPLEMENTAL INSPECTION 58,600 PTC.N EW8100-9 MUST BE RECVD PRIOR TO AIRCRAFT REACHING 58,600 PTC WITH METHOD OF INSPECTION & INTERVAL STAGE 3. IF NEW 8100-9 NOT RECVD PRIOR 58.600. AIRCRAFT UNSERVICEABLE.