What was found
(CAN) WHILE PERFORMING UNSCHEDULED MAINTENANCE, A BULGE WAS OBSERVED ON FUSELAGE SKIN AROUND THE FORWARD WING SPAR PICKUP FITTING. FURTHER INSPECTION REVEALED BOTH LT AND RT FROST SPAR ATTACHMENT BULKHEADS P/NS 41658-0 AND -1 WERE CRACKED AND ALSO LT AND LT FRONT SPAR ATTACHMENT CHANNEL P/N''S 40603-0 AND -1 WERE CRACKED. ATTACHMENT BULKHEADS WERE REPLACED WITH NEW PIPER P/N''S 52694-0 AND 52694-01. FRONT SPAR ATTACHMENT CHANNELS WERE REPLACED. WITH NEW PIPER P/N''S 40603-02 AND 40603-03.