What was found
CLE/IAD FLT 6548 - DURING CRUISE AT 0820 HOURS ON 7-17-97, AIRCRAFT MADE A SCHEDULED LANDING AT IAD WITH ONE DISCREPANCY WHICH WAS THE LT BETA LIGHT ILLUMINATED AND FOUND P-3 LINE CRACKED CAUSING HOT AIR TO MELT WIRES TO BETA SWITCH. MAINTENANCE REMOVED AND REPLACED P-3 LINE AND BETA PRESSURE SWITCH. OPS CHECK OK. AIRCRAFT RELEASED AND RETURNED TO SERVICE. REF: OPERATOR CONTROL NR 97ZZZX3556. (X)