What was found
UPPER ENGINE COWLING SEPARATED FROM AIRCRAFT ON APPOACH TO RDU. DATE OF LAST INSPECTION, 10-24-97, AT 100-HOUR INSPECTION, UPPER ENGINE COWLING WAS REMOVED AND REINSTALLED. SUSPECT FORWARD ATTACH PIN FAILURE AT FIBERGLASS ATTACHMENT. ALL OTHER FASTENERS, 2 EACH RT AND LT, ALSO 2 EACH UPPER AFT WERE DAMAGED AS A RESULT OF FAILURE. NO DEFECTS NOTED OF UPPER PIN ATTACH POINTS OR ANY MISALIGNMENT OF UPPER ENGINE COWLING AFTER 80 HOURS OF FLIGHT, UNTIL THIS FAILURE.