What was found
FLT 6197 - PHL-IAD - DURING CLIMB, AIRCRAFT MADE AN UNSCHEDULED LANDING DUE TO BOTH HYDRAULIC SYSTEMS WENT TO ZERO INDICATION. AIRCRAFT RETURNED TO GATE AND WITH NO FURTHER PROBLEMS. MAINTENANCE IS IN THE PROCESS OF TROUBLESHOOTING PROBLEM. MAINTENANCE INSPECTED AND REMOVED AND REPLACED MLG ACTUATOR UP PRESSURE LINE, OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)