As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUEL BEGAN VENTING FROM RIGHT WING EN ROUTE MSP-BIL. FLIGHT RETURNED TO MSP AND LANDED WITHOUT INCIDENT. FOUND FUEL VENT TUBE COUPLING LOOSE ON OUTBOARD SECTION OF LEFT WING TANK. LEAK AND OPERATIONAL CHECK OK. AIRCRAFT RETURNED TO SERVICE.