What was found
IAD/BNA - FLT 6704 - DURING CRUISE AT 1755 HRS ON 6-27-98, AIRCRAFT MADE AN UNSCHEDULED LANDING DUE TO ALTITUDE ALERT SOUNDED CONTINUOUSLY. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND PERFORMED CHECKED OF FCC SYSTEM AND COULD NOT DUPLICATE PROBLEMS. OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)