As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT - FL 2200 - AFTER TAKEOFF, CREW WAS NOT ABLE TO MAINTAIN PRESSURIZATION. THE FLOW LIGHT WAS ILLUMINATED. FLIGHT RETURNED TO PIT AND LANDED WITH NO FURTHER INCIDENT. MAINTENANCE REPAIRED A LEAKING DUCT. SUBSEQUENTLY, THE PRESSURE SELECTOR ASSEMBLY WAS REPLACED. (M)