What was found
AIRCRAFT WAS GROUNDED: YELLOW HYDRAULIC SYSTEM RESERVOIR LOW LEVEL MESSAGE CAME ON AFTER TAKEOFF. RESERVOIR INDICATES 0 FLUID. GEAR AND FLAPS WERE ALREADY FULLY RETRACTED. APPROXIMATELY 30 MINUTES LATER YELLOW HYDRAULIC SYSTEM RESERVOIR OVERHEAT MESSAGE CAME ON WITH THE YELLOW ELECTRIC PUMP OFF. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT LANDED SAFELY AT DFW. **SUPPLEMENTAL REPORT WILL BE SUBMITTED** (OPEN)