What was found
ENGINE WAS RETURNED TO OUR REPAIR STATION FOR UNSCHEDULED REPAIR. FLIGHT CREW REPORTED HEARING AN “ABNORMAL NOISE” DURING FLIGHT; HOWEVER, ALL ENGINE PARAMETERS WERE REPORTED TO REMAIN WITHIN NORMAL LIMITS. POST-FLIGHT INSPECTION REVEALED MISSING AIRCRAFT INLET RIVET HEADS AND EVIDENCE OF FOD IN THE FRONT OF THE ENGINE. OEM PRODUCT SUPPORT DIRECTED A BORESCOPE INSPECTION OF THE ENGINE’S COMPRESSOR SECTION, WHICH REVEALED DAMAGE TO THE INTERMEDIATE PRESSURE COMPRESSOR ROTOR AND THE HIGH PRESSURE COMPRESSOR ROTOR. DUE TO THE LEVEL OF ENGINE DISASSEMBLY REQUIRED TO FACILITATE REPAIRS, W.I. PRODUCT SUPPORT DIRECTED REMOVAL OF THE ENGINE FOR RETURN TO OUR REPAIR STATION FOR REPAIR. AFTER INDUCTION INTO OUR REPAIR STATION, DISASSEMBLY OF THE ENGINE REVEALED ONE LIBERATED I.P. COMPRESSOR ROTOR BLADE. DAMAGE TO THE FAN STATOR VANES AND DOWNSTREAM HPC ROTOR BLADES ARE INDICATIVE OF SECONDARY DAMAGE RESULTANT FROM THE LIBERATED I.P. ROTOR BLADE.