As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURN TO FIELD DUE TO A PRESSURIZATION PROBLEM. INABILITY TO PRESSURIZE WAS RESULT OF A MALFUNCTIONING SKIN AIR OUTLET VALVE. THE DEFECTIVE UNIT WAS REPLACED AND VERIFIED FAULTY. NO FURTHER PRESSURIZATION PROBLEMS REPORTED SINCE UNIT REPLACEMENT.