As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - FLT 1216 - EN ROUTE DFW-PHL, IN FLIGHT B QUANTITY HYDRAULIC SYSTEM AND PRESSURE DECREASED TO ZERO. RETURNED DFW AND LANDED WITHOUT FURTHER INCIDENT. REPLACED RIGHT SIDE ELEVATOR TRANSFER VALVE AND RIGHT SIDE ELEVATOR POWER CONTROL. (M)