What was found
45 MIN INTO FLIGHT CREW GOT A HYD SYSTEM 1 ENGINE PUMP LIGHT ILLUMINATED. THE CREW THEN TURNED ON HYD 1B ELECTRIC PUMP AND EVERYTHING RETURNED TO NORMAL. SHORTLY THERE AFTER THEY NOTICED THE HYD QTY & PRESSURE ON THE #1 SYSTEM BOTH DROPPING. THEY DIVERTED TO NEAREST SUITABLE AIRPORT (KCVG) WHERE THEY CALLED FOR EMERGENCY EQUIPMENT TO ROLL. WE ARE WORKING ON GETTING ON-CALL MX AS WELL AS CONTRACTED MX ONSITE TO TROUBLESHOOT CAUSE. WE WILL FOLLOW UP AFTER DISCOVERY.