As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHL - FLT1447 - ON CLIMB-OUT FROM PHL, AT 12,000 FT, THE NR 2 ENGINE LOST THRUST AND WENT TO IDLE. PARTIAL THRUST CAME BACK BUT DECREASED AGAIN ON APPROACH. CREW DECLARED AN EMERGENCY AND RETURNED TO FIELD AT PHL. FLIGHT LANDED WITHOUT FURTHER INCIDENT AND TAXIED TO THE GATE ON IT'S OWN POWER. MAINTENANCE REMOVED AND REPLACED THE NR 2 ENGINE ASSEMBLY. OPERATIONAL CHECK AND LEAK CHECK GOOD.