What was found
DURING CRUISE (TPE), THE NR 4 ENGINE EXPERIENCED COMPRESSOR STALLS FOLLOWED BY SMOKE IN THE CABIN AND THE ENTIRE AIRCRAFT SHAKING. THE NR 4 BLEED VALVE WAS CLOSED AND THE SMOKE STOPPED. THE NR 4 ENGINE WAS SHUT DOWN BUT THE AIRCRAFT CONTINUED TO VIBRATE AND THE NR 3 ENGINE INDICATIONS WERE FLUCTUATING. 127,000 POUNDS OF FUEL WAS DUMPED AND THE AIRCRAFT DIVERTED TO TPE WHERE AN UNEVENTFUL THREE-ENGINE LANDING WAS ACCOMPLISHED. THE NR 4 ENGINE FAN WAS FOUND TO BE SEIZED AND THE ENGINE WAS REPLACED. AN INSPECTION OF THE AIRFRAME, PYLONS, AND NR 3 ENGINE WAS ACCOMPLISHED AND CHECKED OK. A GROUND RUN-UP CONFIRMED PROPER OPERATION OF THE ENGINES.