What was found
NR 1 ENGINE VIBRATION. FLT 803-05 DIVERTED TO SEA DUE TO PHYSICAL VIBRATION. VIB FOLLOWED THROTTLE. AVM PEGGED AT 10 UNITS. AFTER SHUTDOWN AT SEA, N1 ROTOR LOCKED UP. ENGINE REPLACED AT SEA. TEARDOWN REVEALED THAT THE THRUST BALANCE AIRSEAL (TB AIRSEAL) WAS CRACKED, WITH 2 CHUNKS LIBERATED. THE 2 CHUNKS INCLUDED A KNIFE EDGE, AND AN ANGLED PORTION OF THE BARREL. THE HARDWARE HAS BEEN RETURNED TO PRATT & WHITNEY FOR FURTHER INVESTIGATION.