Boeing 777-222 Hydraulic System Incident at Ezeiza (N796UA)

Incident Overview and Flight Details On September 9, 2025, at 00:08 UTC, a Boeing 777-222 (ER) with registration N796UA, operated by United Airlines, departed from Ministro Pistarini International Airport (Ezeiza) in Buenos Aires, Argentina, bound for George Bush Intercontinental Airport in Houston, United States. The flight was a scheduled commercial passenger service. ## In-Flight Malfunction and Return Approximately 35 minutes into the flight, while cruising at 28,000 feet (FL 280), the crew received an Engine Indicating and Crew Alerting System (EICAS) indication of low hydraulic fluid quantity in the center hydraulic system. Shortly after, a low-pressure indication appeared for the same system. The crew declared an emergency and decided to return to the airport of origin. ## Emergency Procedures and Landing The crew executed the corresponding non-normal checklists and performed an in-flight fuel dump to reduce the aircraft's weight below the maximum landing limit. The aircraft landed at the airport of origin one hour and 45 minutes after takeoff, with no other issues reported. ## Maintenance and Return to Service Following the landing, the crew reported the incident to United Airlines. In accordance with the manufacturer's technical directive, maintenance personnel at Ministro Pistarini Airport were requested to intervene. During the inspection, the leak was identified as originating from the hydraulic fuse in the right landing gear compartment. The affected fuse was replaced, and its proper operation was verified. The aircraft was released to service and departed again on September 11 at 12:37 UTC, bound for George Bush Intercontinental Airport on flight UA3917. The aircraft arrived at its destination without further incidents.