What was found
AFTER DESCENDING FROM FL390 TO FL330 THE NR 1 ENGINE OIL QTY WENT TO 18%. BY THE TIME WE APPROACH FIND IT WENT TO 0% AFTER LANDING IT RETURNED TO 7%. R&R NR 1 ENG STARTER PER AMM 80-11-01 & R&R NR 1 ENG STARTER CONTROL VALVE PER AMM 80-11-03 PERFORMED NR 1 ENG IDLE LEAK CHK AMM 71-00-00 (OPS CHK GOOD NO LEAKS OR DEFECTS AT THIS TIME) STARTER R&R 60576 STARTER VALVE R&R 60577 P/N OFF/ON 3505945-12 S/N OFF GRTA3446C S/N ON A3488C P/N OFF/ON 3289630-5 S/N OFF 9482 S/N ON 414.