What was found
GUM - FLT 0900 - THE SYSTEM NR 1 AND NR 2 MANIFOLD FAIL LIGHTS ILLUMINATED IN FLIGHT WITH NR 2 DISPLAYING THE LOWEST PRESSURE. THE AIRCRAFT WAS RETURNED TO GUM WHERE THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND A BLOWN RUBBER DUCT ON NR 2 PACK HEAT EXCHANGER. THE DUCT WAS REPLACED AND LEAK CHECK WAS GOOD. THE AIRCRAFT WAS PRESSURIZED TO 4 PSI USING PACKS NR 2 AND NR 3, AND NO ABNORMAL INDICATIONS WERE NOTED. (M)