As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOST HYDRAULIC C QUANTITY IN FLIGHT AND CENTER PRESSURE. AN EMERGENCY WAS DECLARED, RETURNED TO DEPARTURE, AND FLIGHT LANDED WITHOUT FURTHER INCIDENT. THE AIRCRAFT WAS GROUNDED. REPLACED THE LEFT WING NR 3 SPOILER POWER CONTROL ACTUATOR IAW AMM 27-61-02. OPS AND LEAK CHECKED GOOD.