As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APPROXIMATELY 20 MINUTES AFTER TAKEOFF AT FL300 THE RIGHT PACK FAILED. RETURNED TO DEPARTURE, EMERGENCY DECLARED AND FLIGHT LANDED WITHOUT FURTHER INCIDENT. THE AIRCRAFT WAS GROUNDED. REPLACED RIGHT LOWER FLOW CONTROL VALVE UP TO H(4) IAW AMM 21-51-02. MAT LRU TEST PASSED. LEAK CHECKED GOOD.