Hong Kong Boeing 747 Runway Excursion Preliminary Report Released

Runway Excursion in Hong Kong: Unpacking the Preliminary Report on the Boeing 747 Freighter Accident

On October 20, 2025, a routine cargo flight concluded in tragedy at Hong Kong International Airport (HKIA). An ACT Airlines Boeing 747-481 BDSF freighter, operating for Emirates SkyCargo, veered off the runway during its landing roll, resulting in the complete loss of the aircraft and the deaths of two security personnel on the ground. The incident immediately prompted an investigation by Hong Kong’s Air Accident Investigation Authority (AAIA), which has now released its preliminary report. This initial document provides the first official, fact-based look into the sequence of events that led to the incident, offering critical data without yet drawing conclusions.

Preliminary reports are a standard and vital part of any major aviation accident investigation. Their purpose is to disseminate factual information to the public and the aviation industry in a timely manner, outlining what is known in the early stages. This transparency helps to manage speculation and provides immediate, verified details from sources like the Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR). For an industry built on safety and continuous improvement, these early findings are crucial. They lay the groundwork for a deeper analysis that will eventually identify the root causes and contributing factors, leading to safety recommendations aimed at preventing future occurrences.

The accident involves a Boeing 747, an aircraft with a long and storied history. While many passenger airlines have retired the “Queen of the Skies,” hundreds have been converted into freighters, forming the backbone of the global air cargo network. This incident brings renewed focus on the operational and maintenance considerations for these aging, yet indispensable, workhorses of the sky. The investigation’s findings will be closely watched by cargo operators worldwide who rely on similar fleets.

Deconstructing the Incident: Key Findings from the AAIA Report

The preliminary report, designated PLR-2025-04, meticulously lays out the timeline and established facts of the accident involving aircraft TC-ACF. The flight, operating as UAE9788 from Dubai, landed on Runway 07L at approximately 3:52 AM local time. The crew consisted of four members, with the co-pilot designated as the Pilot Flying for the landing. The plan was for a Flap 25 landing utilizing the Autobrake 2 setting. However, the landing roll quickly deviated from the norm.

The Landing Sequence and Loss of Control

According to the report, a critical event occurred shortly after touchdown. As the co-pilot applied reverse thrust to decelerate the aircraft, an “AUTOBRAKES” message appeared on the Engine Indication and Crew Alerting System (EICAS). This alert signaled a disarming of the automated braking system. In response, the captain, who was the Pilot Monitoring, took control of the aircraft. It was at this point that the situation escalated dramatically.

Data recovered from the FDR provides a stark picture of what happened next. The Number 4 engine, instead of providing reverse thrust to slow the aircraft, accelerated to approximately 107% N1 in the forward thrust direction. This asymmetric thrust caused the aircraft to veer sharply to the left, leading it to depart the paved runway surface. Examination of the flight deck after the accident found the Autobrake selector in the “Disarmed” position and the Number 4 engine thrust lever in the full forward position, corroborating the FDR data.

The aircraft’s journey after leaving the runway was destructive. It struck and destroyed various pieces of airport equipment, including meteorological sensors and signage, before crashing through a perimeter fence. The 747 then collided with a stationary security vehicle on a perimeter road, tragically killing the two occupants, before coming to rest in the sea. The impact forces were so severe that the aircraft’s entire tail section separated from the fuselage, and the plane was declared a total loss. All four crew members survived the accident.

The aircraft veered off to the left, resulting in a runway excursion… The aircraft subsequently collided with a stationary security ground vehicle… The impact resulted in the ground vehicle entering the sea. The two security staff in the ground vehicle perished.

Pre-Existing Conditions and Aircraft History

The investigation also looks into the aircraft’s condition before the flight. The report notes that the Boeing 747 was dispatched with two pre-existing issues documented on the Minimum Equipment List (MEL). One was a resolved cockpit indication for the Hydraulic System 1 Reservoir, and the other was an inoperative thrust reverser on the Number 4 engine. The inoperative reverser is a significant detail, as the FDR data later showed that same engine producing high forward thrust during the landing roll.

The aircraft itself, TC-ACF, had a long service history. Manufactured in 1993, it first flew for All Nippon Airways (ANA) as a passenger jet and was famously adorned with a “Pokémon Jet” livery. In 2011, it was converted into a freighter, a common second life for the durable 747 airframe. This history underscores the aircraft’s age and the extensive operational life typical of cargo planes in the modern era.

The Path Forward: A Multi-faceted Investigation

With the preliminary report published, the AAIA’s investigation now enters a more analytical phase. The successful recovery of the CVR and FDR is a critical milestone, as these “black boxes” provide invaluable data on the aircraft’s performance and the crew’s actions in the final moments of the flight. The investigation is being conducted in accordance with international standards set by the International Civil Aviation Organization (ICAO).

This international cooperation is essential for a thorough and impartial investigation. Accredited representatives from several key bodies are participating. These include the Transport Safety Investigation Center (TSIC) of Turkey, representing the state where the aircraft was registered and the airline is based, and the National Transportation Safety Board (NTSB) from the United States, representing the state of the aircraft’s design and manufacture. This collaborative approach ensures that all relevant expertise is brought to bear on the case.

The investigation will now focus on several key areas. Technical analysis will delve deeper into the aircraft’s braking and engine systems, particularly the failure of the autobrake system and the anomalous behavior of the Number 4 engine. Maintenance and engineering records will be scrutinized to understand the aircraft’s service history and the handling of the inoperative thrust reverser. Furthermore, the investigation will examine operational issues, including crew qualifications and experience, as well as human factors and the airline’s Safety Management Systems. The final report will synthesize all these elements to determine the cause and contributing factors, with the ultimate goal of issuing safety recommendations to prevent a similar tragedy.

Concluding Section

The preliminary report on the runway excursion of TC-ACF provides a factual, yet sobering, account of a catastrophic landing failure. It outlines a sequence of events where a disarmed autobrake system was followed by a critical surge of forward thrust from one engine, leading to a complete loss of directional control. While it refrains from assigning cause, the report lays a clear foundation for the next phase of the investigation, highlighting the complex interplay between mechanical systems and human action in the cockpit.

As the global air cargo industry continues to rely heavily on veteran aircraft like the Boeing 747, the findings from this investigation will be of paramount importance. The final report from the AAIA will not only provide closure on this specific incident but will also likely yield crucial safety lessons for operators, maintenance providers, and manufacturers. The goal, as always in aviation, is to learn from tragedy to build a safer future, ensuring the “Queen of the Skies” can continue her vital work without repeating such a devastating event.

FAQ

Question: What is a preliminary accident report?
Answer: A preliminary report is an initial document released by an air accident investigation authority. It provides established factual information from the early stages of an investigation, such as data from flight recorders, but does not include analysis, causes, or conclusions. Its purpose is to inform the public and aviation industry in a timely manner.

Question: What happens next in the investigation?
Answer: Investigators will now conduct a detailed analysis of the collected data, including the CVR and FDR. The investigation will focus on technical systems, maintenance records, operational procedures, and human factors. The AAIA will work with international partners like the NTSB to determine the root causes and contributing factors before publishing a final report with safety recommendations.

Question: Who is investigating the accident?
Answer: The Air Accident Investigation Authority (AAIA) of Hong Kong is leading the investigation. They are supported by accredited representatives from Turkey’s Transport Safety Investigation Center (TSIC) and the United States’ National Transportation Safety Board (NTSB).

Sources: AAIA Preliminary Report PLR-2025-04