As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNABLE TO PRESSURIZE AFTER TAKEOFF. GROUND CHECK OK. AIRCRAFT RETURNED TO DNA AND LANDED UNEVENTFUL. FOUND LOOSE LINE AT RT FLOW CONTROL VALVE, TIGHTENED IAW NASI SYSTEM STC ST466CH, OPS CHECKED FOUND NORMAL. AIRCRAFT RETURN TO SERVICE.