What was found
(CAN) DURING TEST FLIGHT AFTER EXTENSIVE AIRFRAME SCHEDULED MX, A HEAVY OIL SMELL IN CABIN WAS DETECTED. PROCEEDED WITH TEST FLIGHT AS THERE WERE NO ASSOCIATED SMOKE & VAPOR & ACFT LANDED UNEVENTFULLY. AFTER PRELIMINARY INSPECTION, OPERATOR REPORTS OIL PRESENCE AROUND THE FAN AREA POINTING TO A NR 1 OR 2 BEARING OIL LEAK INTO THE GAS PATH.