The Civil Aviation Authority of the Philippines (CAAP) has released its final investigation report on Korean Air flight KE-631, which overran Runway 22 at Mactan-Cebu International Airport on October 23, 2022. The flight was carrying 162 passengers and 11 crew members on a routine flight from Seoul-Incheon to Cebu.
The final investigation report was uploaded via the website of South Korea’s Aviation and Railway Accident Investigation Board (ARAIB) on March 13.
The CAAP’s Aircraft Accident Investigation and Inquiry Board (AAIIB) concluded that three primary factors contributed to the accident: the captain’s forward pitch control inputs that led to premature ground contact, vertical wind conditions during the approach, and critical damage to the right main landing gear (MLG) that resulted in the loss of most aircraft deceleration systems.
According to the report, the Airbus A330-322 aircraft (registration HL7525) was on its second approach attempt in heavy rain conditions when it made ground contact approximately six meters before the runway threshold. The impact caused the right MLG to hit a 15-centimeter concrete edge, fracturing the lower articulation link and damaging the pitch trimmer.
“The right hand MLG hit a 15cm step of the cemented edge of RWY 22 resulting in multiple damage/faults to the said landing gear and consequently the loss of most of the deceleration means, specifically aircraft braking failure resulting in runway overrun,” the report states.
Flight data analysis revealed the aircraft experienced several downdrafts during its final approach, with the vertical speed increasing from approximately 800 ft/min to almost 1,300 ft/min at 100 feet radio altitude. However, investigators determined that the pilot’s sidestick inputs had a “higher contribution” to the aircraft’s unstabilized approach than the wind conditions.
The investigation further identified that damage to the MLG resulted in the loss of multiple critical systems, including:
- Normal braking (due to loss of wheel tachometers)
- Ground spoilers (due to loss of landing gear control interface units)
- Thrust reversers (due to weight-on-wheel discrepancy between the landing gears)
- Alternate and emergency braking (due to hydraulic fluid loss)
A previously undetected “dormant failure” in the alternate braking system’s pressure release valve was also discovered, which contributed to the blue hydraulic system’s rapid fluid loss after the initial damage occurred.
The aircraft ultimately overran the runway at approximately 83 knots, colliding with the localizer antenna and approach lighting system before coming to rest about 235 meters beyond the runway end. One flight crew member, four cabin crew members, and fifteen passengers sustained minor injuries.
The CAAP has issued safety recommendations to the Mactan-Cebu International Airport Authority (MCIAA) to enhance runway threshold conditions in compliance with international standards. These recommendations also call for revisions to MCIAA’s Disabled Aircraft Removal Plan (DARP) to clearly define the AAIIB’s role in releasing accident aircraft custody. Additionally, the report stressed the need for readily available lifting bags to facilitate aircraft recovery.
Korean Air has since implemented several safety enhancements following the accident, in the form of improving pilot training, restructuring operations, and introducing dedicated Airbus and Boeing dispatch teams. The airline also upgraded flight monitoring with an instant communication system and a more advanced tracking system.
Additional measures include a turbulence alert platform, simplified emergency procedures for cabin crew, and stronger safety management at high-risk airports, reinforcing its commitment to safer operations.
The accident investigation involved collaboration between Philippine investigators and representatives from Korea’s ARAIB, France’s Bureau d’Enquêtes et d’Analyses (BEA), with technical support from Airbus.
The fate of HL7525
Because of the extensive damage the aircraft sustained in the incident, HL7525 was deemed damaged beyond economic repair.
Today, the ill-fated Airbus A330 has been relocated to a “temporary relocation area” south of Runway 04’s threshold. The aircraft was moved off the runway to allow flights to resume in Cebu, the Philippines’ second-busiest airport, as soon as possible.
The 24-year-old aircraft, at the time of the incident, has since been stripped of salvageable parts, with its original Korean Air branding removed and covered in green paint. As of now, the aircraft remains visible when traversing General Aviation Road outside the perimeter fence.
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