What was found
AFTER REACHING CRUISE AT FL350, THE NR 4 ENGINE FLAMED OUT. WHILE DESCENDING, THE CREW ATTEMPTED THREE RESTARTS OF THE NR 4 ENGINE WITH THE LAST ONE SUCCESSFUL AT FL250. ALL ENGINE PARAMETERS INDICATED NORMAL AFTER THE RESTART SO THE AIRCRAFT CLIMBED BACK TO FL350 AND CONTINUED TO NRT WITHOUT ANY FURTHER PROBLEMS. MAINTENANCE INSPECTED THE ENGINE WITH NO DEFECTS NOTED. THE FUEL FILTER AND PH FILTER WERE REPLACED AND THE AIRCRAFT CONTINUED IN SERVICE.