What was found
ON FLIGHT 4001 AFTER TAKEOFF ON INITIAL CLIMBOUT THE CREW REPORTED, NOTICED AN OIL SMELL IN COCKPIT. THE FLIGHT ATTENDANT REPORTED A SLIGHT SMELL IN THE FORWARD CABIN. THE PASSENGERS DID NOT SEEM TO NOTICE ANY ODORS. THE AUXILIARY POWER UNIT WAS OFF. NO VISIBLE SMOKE WAS NOTICED. THE CREW ELECTED TO RETURN TO FSD. THE CREW DID NOT DECLARE AN EMERGENCY. THE AIRCRAFT LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. THE CORRECTIVE ACTION INFORMATION IS PENDING.