As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLE - FLT 9550 - ON CLIMB-OUT FROM CLE, EN ROUTE TO PHL AT FL110, PILOT REPORTED THAT FLIGHT LOST CABIN PRESSURIZATION. AUTO, STANDBY AND MANUAL MODES WOULD NOT CONTROL OUTFLOW VALVE. CIRCUIT BREAKERS WERE RESET WITH NO CHANGE. LANDING GEAR WAS CYCLED DOWN, THE UP. CREW REGAINED CABIN PRESSURIZATION IN ALL MODES AND CONTINUED FLIGHT. MAINTENANCE FOUND THE AFT OUTFLOW VALVE DEFECTIVE. REMOVED AND REPLACED AFT OUTFLOW VALVE. OPERATIONAL CHECK OF PRESSURIZATION SYSTEM PER MM 21-31-00 NORMAL. (M)