What was found
DURING FLIGHT, NR 1 HYDRAULIC PUMP PRESSURE WENT TO O PSI WHEN RAISING MLG. ACCOMPLISHED AIR TURNBACK, AIRCRAFT LANDED WITHOUT INCIDENT. FOUND NR 1 HYD PUMP FAILED. REPLACED PUMP AND FILTER, INSPECTED UTILITY SYSTEM MAIN AND DRAIN FILTERS, NO CONTAMINATION NOTED. SYSTEM OPS CHECKED AND LEAK CHECKED PER MM CH 29-11-00.