What was found
WILLIAMS INTERNATIONAL ENGINE MODEL FJ44-3A, SERIAL NUMBER 141186, FROM AIRCRAFT 525B-0088 (N525MP) WAS RETURNED TO OUR REPAIR STATION FOR UNSCHEDULED REPAIR. N525MP IS OPERATED UNDER FAR PART-135. ACCORDING TO THE WILLIAMS INTERNATIONAL OEM PRODUCT SUPPORT TEAM, ONE OF THEIR AUTHORIZED SERVICE CENTERS WAS PERFORMING REPLACEMENT OF THE NO. 1 CARBON SEAL TO RESOLVE AN OIL LEAK SQUAWK ON SUBJECT ENGINE, AND DURING THAT PROCESS, DISCOVERED A LIBERATED BLADE ON THE INTERMEDIATE PRESSURE (I.P.) COMPRESSOR ROTOR. DUE TO THIS FINDING, W.I. OEM PRODUCT SUPPORT DIRECTED THE PART-145 SERVICE CENTER TO REASSEMBLE THE ENGINE (TO FACILITATE SHIPMENT), REMOVE IT FROM THE AIRFRAME, AND RETURN IT TO OUR REPAIR STATION FOR REPAIR. AFTER INDUCTION INTO OUR REPAIR STATION, WE DISASSEMBLED THE ENGINE AND CONFIRMED ONE LIBERATED 3RD-STAGE I.P. COMPRESSOR ROTOR BLADE. NOTE: THE I.P. COMPRESSOR ROTOR IS A THREE-STAGE AXIAL COMPRESSOR. FURTHER INSPECTIONS REVEALED A CRACK IN THE INTERSTAGE HOUSING’S BEARING CAVITY, WHICH IS DEEMED TO BE ROOT-CAUSE OF THE OIL LEAK ORIGINALLY SQUAWKED BY THE AIRCRAFT OPERATOR.