As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNABLE TO CONTROL PRESSURIZATION EITHER AUTO OR MANUAL. FLIGHT DECLARED AN EMER. RETURNED TO FIELD & LANDED WITHOUT FURTHER INCIDENT. ACFT WAS REMOVED FROM SERVICE. CHECKED & FOUND OUTFLOW VLV CONTROL WHEEL MOUNT SCREWS CAME LOOSE, CAUSING WHEEL TO JAMB. SECURED MOUNT SCREWS. OPERATIONS CHECKED NORMAL IAW MM 21-32-00.