What was found
1) IN FLIGHT CREW NOTED 200 LB IMBALANCE, OBSERVED FUEL LEAKING FROM LH WINGTIP AREA 2)CREW DIVERTED TO BHM 3)LANDING WAS UNEVENTFUL 4) STERLING MTN WITH PILATUS TECH SUPPORT DETERMINED THE ISSUE WAS CAUSED BY EXCESSIVE PRESSURE DURING FUELING CAUSING FUEL TO BE FORCED INTO THE CLIMB VENT LINE. ONCE AIRBORNE DIFFERENTIAL PRESSURE CAUSED THIS FUEL TO BE SIPHONED OUT UNTIL FUEL LEVEL DROPPED BELOW LEVEL OF VENT OUTLET DURING DESCENT. 5)LEAK CHECK OF SYSTEM REVEALED NO CURRENT LEAKS 6)AIRCRAFT RELEASED TO CLT