What was found
THE FLIGHT-CREW HAD NOTICED SMOKE IN THE CABIN, WHICH THEY ISOLATED TO THE NR 1 ENGINE, PROMPTING IN-FLIGHT SHUTDOWN OF ENGINE. AIRCRAFT LANDED WITHOUT INCIDENT. POST-FLIGHT INSPECTION REVEALED NO OIL VISIBLE IN THE NR 1 ENGINE’S OIL LEVEL SIGHT-GLASS. SUPPORT RECOMMENDED A BORESCOPE INSP & INSP OF MAGNETIC CHIP COLLECTORS, WAS PERFORMED. CHIP COLLECTORS EXHIBITED METALLIC DEBRIS & BORESCOPE INSP REVEALED EVIDENCE OF ENG OIL IN THE CORE OF THE ENGINE. BASED ON THESE FINDINGS, SUPPORT DIRECTED REMOVAL OF THE ENGINE FOR SHIPMENT TO REPAIR STATION FOR INVESTIGATION & REPAIR. ENGINE DISASSEMBLY REVEALED TWO PARTIALLY-RELEASED HIGH PRESSURE TURBINE (HPT) BLADE TIPS & THE NR 3 BEARING EXHIBITED DAMAGE. ASSOCIATED STATIC ENGINE COMPONENTS EXHIBITED SECONDARY DAMAGE FROM THE HPT BLADE & NR 3 BEARING ANOMALIES. DAMAGE TO THE NR 3 BEARING IS DEEMED TO BE CAUSED BY N2 SPOOL IMBALANCE RESULTANT FROM THE HPT BLADE ANOMALIES.