What was found
FLT 7241 - CMH-IAD - DURING APPROACH, AIRCRAFT NR 3 HYDRAULIC SYSTEM QTY WENT TO ZERO. CREW UTILIZED ABNORMAL PROCEDURE AND LOWERED LANDING GEAR MANUALLY. MAINTENANCE REMOVED AND REPLACED INBOARD SIDE FITTING O-RING OF NR 3 HYDRAULIC SYSTEM ACCUMULATOR, AND PERFORMED POST MAINTENANCE GEAR OPERATION NORMALLY AND MANUALLY. OPS CHECK AND LEAK CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)