What was found
ACFT DEPARTED FOR NORMAL BOMBING OPERATIONS. APPROX 1 HR INTO FLIGHT PILOT EXPERIENCED RT ENGINE EXCESSIVE BACK-FIXING/POPPING NOISES WITH RAPID LOSS OF INDICATED BRAKE MEEN AFFECTING PRESSURE. PILOT THEN ELECTED TO PERFORM AN EMERGENCY ENGINE SHUTDOWN, AND RETURN TO BASE. UPON INSP, FOUND MASSIVE QUANTITIES OF METAL IN ENGINE REAR OIL SUMP PLUG AND MAIN ENGINE SCREEN. IT WAS ALSO NOTED THAT UPON INSP OF METAL CONTAMINANTS THAT A CONICAL WASHER WAS FOUND IN REAR OIL SUMP. ENGINE WAS THEN REMOVED FROM SERVICE.