As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, HYDRAULIC SYSTEM NR 1 FLUID BEGAN DECREASING AND WENT TO 0. FLIGHT CONTINUED ON TO ANC. FOLLOWED COM PROCEDURE AND SYSTEM NR 1 WAS SHUT DOWN. CFR WAS CALLED OUT TO MEET THE FLIGHT AND LANDING WAS UNEVENTFUL. AIRCRAFT WAS THEN TOWED TO THE CARGO RAMP. MAINTENANCE REMOVED AND REPLACED NR 1 ENGINE ADP, EDP AND PRESSURE AND CASE DRAIN MODULE FILTERS. OPERATIONAL CHECKED GOOD AND AIRCRAFT WAS RETURNED TO SERVICE. (A)