As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. ORD-TPA FLIGHT RETURNED TO ORD ACCOUNT UNABLE TO PRESSURIZE AT 5000 FEET. LANDING UNEVENTFUL. REMOVED AND REPLACED COOLING TURBINE OUTLET HOSE AND CLAMPS(AALA20170118011) IAW AMM 21-51-00. OPERATIONAL CHECK GOOD.