As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT - FLT 481 - CAPTAIN COULD NOT GET AIRCRAFT TO PRESSURIZE SO HE DECIDED TO RETURN TO FIELD AT PIT. FLIGHT LANDED WITHOUT INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE FOUND THE RIGHT TURBOFAN SEIZED. REPLACED SAME. OPERATIONAL CHECK AND PRESSURIZATION CHECK GOOD. (M)