What was found
ON ROTATION, A DEFINITE THUMP FROM REAR OF AIRCRAFT. RETURNED TO DEPARTURE TO INVESTIGATE POSSIBLE CAUSE. PERFORMED GVI OF AIRCRAFT IAW SERVICE CHECK ON W/C, ALSO INSPECTED MCD FOR LOOSE CANS, NONE FOUND. NO CARGO PRESENT IN LOWER FWD, AFT OR BULK COMPARTMENTS. NO ABNORMAL ENGINE INDICATIONS WERE NOTED. INSPECTED TAIL GEAR, NO STRIKE. INSPECTED THE E & E AND TAIL COMPARTMENTS GVI IS GOOD. NO MAINTENANCE PERFORMED.