Incident Overview
The Air Accident Investigation Authority (AAIA) of Hong Kong published an interim statement on 17 June 2025 regarding a serious incident involving an Atlas Air Boeing 747-400F freighter, registration N406KZ. The occurrence took place at Hong Kong International Airport (VHHH) on 17 June 2024.
Flight and Landing
The aircraft departed from runway 25L at 04:09 a.m. local time. Approximately 26 minutes into the flight, the pilot in command made an operational decision to return to Hong Kong following the loss of the hydraulic #1 system. After conducting fuel jettison to meet landing weight requirements, the airplane touched down on runway 25R at 07:12 a.m. The landing was described as normal, with no reported loss of directional control. However, during the landing roll, the fluid levels in hydraulic systems #2 and #4 rapidly depleted to zero. Corresponding warning messages appeared on the Engine Caution and Crew Alert System (EICAS). Evacuation was not deemed necessary.
Post-Flight Findings
Inspection after the flight revealed that tires #9 and #10 were shredded. Parts of wheels #9 and #10 were missing, and significant damage was observed on wheel #9. Several hydraulic lines located in the right-hand wing landing gear (RH WLG) wheel well were found fractured and punctured. As a result, hydraulic fluid in systems #1, #2, and #4 was completely lost. Additionally, damage was sustained by the lower forward fuselage, lower right wing sections, and components and systems inside the wheel well.
Investigation Status
The investigation team has reviewed factors leading to the tire failures and the loss of multiple hydraulic systems. They have studied operational safety risks subsequent to these failures and conducted in-depth examinations of retained aircraft components. Some components were sent to overseas testing facilities, where detailed examination and testing have been completed. The operator’s procedures and crew actions have also been reviewed. The investigation report is being compiled in accordance with Hong Kong regulations. This interim statement is provided as required by paragraph 6.6 of Annex 13 to the Convention on International Civil Aviation.