What was found
SEA - EXPERIENCED A TOTAL LOSS OF NR 2 MAIN HYDRAULIC SYSTEM PRESSURE. THE GEAR WAS EXTENDED VIA ALTERNATE EXTENSION SYSTEM, AND THE AIRCRAFT LANDED IN SEA WITHOUT INCIDENT. AN INSPECTION OF THE NR 2 HYDRAULIC SYSTEM REVEALED THAT THE NR 2 EDP HAD FAILED, DUE TO A HOLE RUPTURED THROUGHT THE SIDE OF THE PUMP HOUSING. IT IS ESTIMATED THAT THE PUMP OPERATED FOR AT LEAST 10 MINUTES IN A DRY STATE, AND WHEN REMOVED, WAS FOUND TO HAVE A SHEARED SHAFT. MAINTENANCE REPLACED THE NR 2 EDP PUMP. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.