As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STRONG VIBRATION FELT IN AFT SECTION OF AIRCRAFT DURING FLIGHT. HYDRAULIC SYSTEM PRESSURE COULD NOT BE MAINTAINED USING NR 1 HYDRAULIC PUMP. NR 1 HYDRAULIC PUMP HAD FAILED. FOUND METAL CONTAMINATION IN BOTH PRESSURE AND RETURN FILTERS, PUMP HAD BEEN MODIFIED AT TIME OF INSTALLATION BY C/W VICKERS SL -29-940070-1. HYDRAULIC PUMP SENT TO MANUFACTURER FOR TEAR-DOWN. AWAITING RESULTS AT THIS TIME.