A United Parcel Service (UPS) Boeing 747-8F cargo aircraft declared a PAN-PAN emergency shortly after departure from Hong Kong International Airport (VHHH) on 26 April 2025, following an in-flight failure of its left inboard engine. The crew conducted a controlled return to Hong Kong after fuel dumping, landing safely on the departure runway approximately 1 hour and 50 minutes after initial takeoff. The aircraft was grounded temporarily and returned to service five days later following inspection and maintenance.
This report reconstructs the event in full detail, using verified information available from flight tracking data, airline disclosures, ATC records, and standard 747-8F systems knowledge.
Flight Overview
Date: 26 April 2025 Operator: UPS Airlines Flight Number: 5X59 Aircraft Type: Boeing 747-8F Registration: N618UP Departure Airport: Hong Kong International Airport (VHHH) Destination Airport: Anchorage Ted Stevens International Airport (PANC) Crew on Board: 4 (all UPS personnel, no passengers) Time of Incident: Shortly after departure from runway 07R Nature of Emergency: Engine #2 (left inboard) failure Emergency Declared: PAN-PAN Initial Response Altitude: 6,000 ft Return Altitude for Fuel Dump: 9,000 ft Landing: Runway 07R, approximately 1 hour 50 minutes after departure Injuries: None Damage: No reported structural damage Flight Status: Cancelled post-return. Aircraft returned to service on 1 May 2025
Sequence of Events
Preflight and Takeoff
Flight 5X59 was scheduled to operate a routine trans-Pacific freighter service from Hong Kong to Anchorage, with onward routing to Ontario, California (ONT). The aircraft, a Boeing 747-8F (serial number 37566, delivered 2014), was loaded with time-sensitive cargo and operating under standard ETOPS and EDTO regulatory oversight for oceanic operations.
Weather at the time of departure was reported as VMC (Visual Meteorological Conditions) with moderate winds from the east, temperature 25°C, visibility exceeding 10km, and no reported wind shear or turbulence.
The aircraft departed runway 07R under normal takeoff power. Initial climb was nominal, with gear retraction and flap setting transitions proceeding as per Boeing SOP.
Engine Failure and PAN-PAN Declaration
Shortly after passing 5,000 feet, the crew reported abnormal indications from engine #2—the left inboard engine powered by a General Electric GEnx-2B67. Cockpit Engine Indicating and Crew Alerting System (EICAS) messages alerted the crew to a possible mechanical anomaly. Audible and visual warnings may have included:
ENG FAIL L2 ENG OIL TEMP HIGH Vibration levels exceeding operational thresholds Possible reduction in N1/N2 spool values or fuel flow fluctuations
Approximately two minutes later, the crew declared a PAN-PAN with Hong Kong Departure Control, advising of an engine malfunction. At that point, they discontinued the climb and levelled at 6,000 feet to complete the appropriate Non-Normal Checklist (NNC) for an engine failure in-flight.
It was determined that the affected engine had to be shut down. The crew began configuring for a return to Hong Kong.
Fuel Dump and Holding
Due to the aircraft’s heavy departure weight—likely near its Maximum Takeoff Weight (MTOW) of 987,000 lbs (447,700 kg)—the aircraft exceeded its Maximum Landing Weight (MLW), which for the 747-8F is approximately 710,000 lbs (322,000 kg). Fuel dumping was required to safely reduce aircraft mass before landing.
Air Traffic Control cleared the aircraft to climb to 9,000 feet and assigned an offshore holding pattern over the South China Sea, clear of other inbound and outbound traffic.
Using the Boeing 747-8’s fuel jettison system, the crew initiated fuel dump procedures via the fuel control panel on the overhead. Fuel was expelled via dedicated dump nozzles located near the wingtips, controlled symmetrically to prevent centre of gravity shifts. Dumping likely continued for 45–60 minutes, monitored via the EICAS fuel quantity indicators and the Flight Management System (FMS).
Dumping procedures are carefully regulated, both environmentally and operationally. The aircraft remained in controlled airspace and above populated areas to prevent contamination.
Return and Landing
Following fuel jettison, a return approach to runway 07R was conducted under radar vectors. The aircraft configured for a standard three-engine approach, using increased thrust settings on the remaining engines.
A Boeing 747-8F can safely land with one engine inoperative, though the approach requires extended landing distances, higher Vref speeds, and possible asymmetrical thrust corrections. The crew would have configured flaps per the “Engine Failure After Takeoff” checklist, and verified all primary and alternate braking systems were armed.
Landing was completed without further incident. Emergency services were on standby and performed a visual inspection of the aircraft as it vacated the runway.
Aircraft Profile
Type: Boeing 747-8F Registration: N618UP MSN: 37566 Engines: 4 × General Electric GEnx-2B67 MTOW: 987,000 lbs (447.7 tonnes) MLW: 710,000 lbs (322.0 tonnes) Fuel Capacity: ~63,000 US gallons (238,600 litres) Range: ~8,130 nmi (15,000 km)
The Boeing 747-8F is the latest and most advanced variant of the iconic 747 family. It features improved aerodynamics, fuel efficiency, and payload capacity, making it one of the preferred aircraft for intercontinental cargo operations.
UPS operates 28 Boeing 747-8Fs as part of its long-haul fleet, most based out of its Worldport hub in Louisville (KSDF).
Engine Information
Model: GEnx-2B67 Type: High-bypass turbofan Manufacturer: General Electric Aviation Thrust Rating: ~66,500 lbf
The GEnx engine family is used on both the Boeing 787 and 747-8 series. The 2B67 variant powers the 747-8 and features composite fan blades, a low-emission combustor, and advanced cooling systems. It is designed for durability and reduced maintenance intervals.
Engine #2 is the inboard engine on the port (left) wing. In a four-engine configuration, failure of a single engine still allows the aircraft to continue flight safely under ETOPS and ICAO Annex 6 guidelines.
Emergency Declaration: PAN-PAN vs. MAYDAY
The flight crew declared a PAN-PAN, which in aviation indicates an urgent situation requiring priority handling but not immediate danger to life or aircraft.
In contrast, a MAYDAY is reserved for grave and imminent danger requiring immediate assistance. The use of PAN-PAN suggests the crew was confident in aircraft control, had contained the malfunction, and required only precautionary return handling.
This choice of declaration reflects disciplined decision-making and accurate threat assessment under pressure.
Aftermath and Investigation
Following the return to Hong Kong, the aircraft was removed from service pending a full engineering inspection. No visible signs of uncontained engine failure were reported, suggesting a contained engine shutdown due to internal component fault or sensor discrepancy.
UPS maintenance teams, in coordination with General Electric representatives, are believed to have conducted a borescope inspection of the #2 engine and reviewed digital fault data recorded by the Central Maintenance Computer (CMC) and Engine Health Monitoring (EHM) systems.
Possible causes may include:
Oil system contamination or low pressure Turbine blade damage or foreign object ingestion Fuel metering unit malfunction Vibration thresholds triggered by rotor imbalance
As of 1 May 2025, N618UP was returned to active service, indicating no major airframe or engine system damage. The aircraft likely underwent engine test runs, operational check flights, and system resets before recertification.
Operational and Regulatory Context
UPS is a FAA Part 121 cargo operator with one of the world’s largest fleets. It operates trans-Pacific flights under Extended Diversion Time Operations (EDTO) rules, which require twin- and four-engine aircraft to comply with strict engine reliability, routing, and communication standards.
This incident did not involve a cargo fire, decompression, or structural issue. Standard FAA reporting protocols (e.g. AC 120-77) would apply, including submission of irregular operations data to the airline’s Safety Management System (SMS).
The Hong Kong Civil Aviation Department (HKCAD) is the responsible oversight authority and would coordinate with the NTSB and FAA if a full investigation is warranted, though none has been formally announced at this time.
Conclusion
This incident highlights the professionalism of UPS flight crews and the robustness of Boeing 747-8F systems in managing in-flight abnormalities. The crew’s disciplined execution of non-normal procedures, from engine shutdown to fuel dumping and safe landing, prevented escalation of the event and ensured aircraft and cargo integrity.
Engine failures, though rare, remain part of the risk profile for long-haul cargo operations. This event serves as a case study in effective emergency resource management (ERM), procedural adherence, and system redundancy.
At no point was the aircraft in imminent danger, and the controlled use of airspace, coordinated ATC communication, and advanced aircraft design allowed for a safe return without injury, damage, or disruption to wider airport operations.
Disclaimer
This article is based on publicly available information and reports at the time of writing. While every effort has been made to ensure accuracy, we cannot guarantee the completeness of the information provided.
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