What was found
OIL QTY WENT TO ZERO AFTER LEVEL OFF. OIL PRESSURE STEADY DROPPED FROM 30PSI TO 12PSI AT LANDING. PERFORMED TEST OF THE NR 3 IDLE LEAK TEST IAW AMM 71-00-00-795. NR 3 FOUND LEAK FROM STARTER WITNESS CHAMBER. REMOVED STARTER IAW AMM 80-11-04. FOUND STARTER SHAFT SEAL MISSING. INSTALLED STARTER SHAFT SEAL AND STARTER IAW AMM 80-11-04. PERFORMED LEAK IDLE TEST PER AMM 71-00-00. NO FURTHER LEAKS NOTED.