What was found
YKM- SHORTLY AFTER TAKEOFF, NR 2 ENGINE OIL PRESSURE LIGHT ILLUMINATED. THE NR 2 OIL PRESSURE GAUGE WAS FLUCTUATING BELOW 40 PSI. AFTER LEVEL-OFF THE WARNING LIGHT WENT OUT AND OIL PRESSURE RETURNED TO NORMAL. RETURNED TO THE FIELD AND ACCOMPLISHED AN UNEVENTFUL LANDING. INSPECTED ENGINE AND SERVICED IT WITH 2 PINTS OF MOBIL JET II OIL. NO PARTS REPLACED.