# Korean Air Flight 631

Korean Air Flight 631 was a scheduled international passenger flight operating from Incheon International Airport near Seoul, South Korea to Mactan–Cebu International Airport in Metro Cebu, Philippines. On 23 October 2022, the Airbus A330-300 operating this flight overran the runway while landing in Cebu due to a failure with the hydraulics system.
The aircraft was damaged beyond repair and written off as a result of the accident, and also resulted in the 14th hull loss of an Airbus A330 worldwide.
The accident resulted in the 17th Korean Air crash since 1970 that resulted in a total write off of aircraft and the first since Korean Air Cargo Flight 8509 crashed in Great Hallingbury, United Kingdom, nearly 23 years prior.

## Background
### Aircraft

The aircraft involved in the accident was a 24-year-old Airbus A330-322, with manufacturer serial number 219, registered as HL7525. The aircraft first flew on 12 May 1998, and was delivered brand new to Korean Air on 26 June 1998. The aircraft was powered by two Pratt & Whitney PW4168 engines.

### Crew

The unnamed captain on board was 52, and had 13,043 flight hours, with 9,285 being on the A330. The also unnamed first officer was 37, and had 1,603 flight hours, of which, 1,035 were on the A330.

## Accident

The flight departed Seoul at 19:20 KST (10:20 UTC) and was scheduled to land at Cebu at 22:00 PHT (14:00 UTC). At about 22:12 PHT (14:12 UTC), KE631 was on final approach to Mactan–Cebu's runway 22 when it executed a go-around. A second landing attempt at 22:26 was unsuccessful. Subsequently, the aircraft circled northeast of Cebu for approximately 30 minutes before conducting a third approach. On the third attempt, the aircraft successfully touched down at 23:08, but was unable to stop on the runway.
The aircraft continued past the end of the runway, striking an instrument landing system lighting array before stopping 300 metres (980 ft; 330 yd) beyond the runway threshold. According to eyewitness accounts, "The instrument landing system lighting array laid over the wings of the aircraft once the aircraft was stopped in the marsh."
Weather reports indicated that the wind speed was 9 knots (17 km/h; 10 mph) from the south-west at 220 degrees. As the aircraft landed on runway 22, there was a 9-knot headwind present. Visibility was 8,000 metres (8.0 km; 5.0 mi) at the time of the accident, with thunderstorms and rain in the area; there were no reports of lightning. Cumulonimbus clouds were scattered at 1,800 metres (5,900 ft) and overcast at 9,000 metres (30,000 ft) above Cebu. Other planes decided to divert due to weather prior to KE631's landing attempts, but there is no information on the time span between the other diversions and the Korean Air flight.

## Aftermath

As the result of the accident, flights to Cebu were forced to either return to their origin airport, divert to Francisco Bangoy International Airport in Davao or to Ninoy Aquino International Airport in Manila. More than 100 flights were cancelled entirely.
Korean Air published an apology on their Instagram account, stating "A thorough investigation will be performed together with the local aviation authorities and Korean authorities to determine the cause(s) of this event."
Commentators noted that "there are many unanswered questions" including why the flight crew of this flight chose to attempt the landing when no other pilots deemed it safe. News reports noted the similarities to previous crashes on Korean Air that were caused by pilot error and the airline's historic safety culture.
After another incident where an engine of another Korean Air Airbus A330 had malfunctioned after takeoff, Korean Air announced it will be grounding the entirety of its Airbus A330 fleet, pending a safety audit.
Since 31 October 2022, Korean Air changed the Seoul–Cebu route flight number from KE631 to KE615. The return flight to Seoul, KE632, was also changed to KE616.
For a while HL7525 remained at the end of the runway with its livery, logo and vertical stabilizer removed. After two months of constructing a road to tow out the aircraft, HL7525 was towed to the southern corner of the airfield, where the almost complete hull has since remained there.

## Investigation

The accident is being investigated by the Civil Aviation Authority of the Philippines (CAAP), with assistance from 40 officers from the Korean Office of Civil Aviation (KOCA) who arrived at Bohol after the accident.

### Preliminary Report

On 24 October 2022, Philippines authorities as well as Korean Ministry of Land, Infrastructure and Transport (MOLIT) released a preliminary report that concluded that a hydraulic failure had caused the failure of brakes on the aircraft.
On 25 October 2022, it was reported that the captain of the flight provided testimony that they suffered a hard touchdown on their second approach due to wind shear forcing them down. During the following go-around, a warning light regarding the brakes lit up. The crew therefore declared an emergency. On the third landing attempt, a warning light regarding the pressure of the brakes lit up and the pilots could not slow down the aircraft.

### Interim Report

On 23 October 2023, CAAP released the first interim statement, stating that the draft investigation report was in its final stage of preparation. On 22 October 2024, CAAP released the second interim statement, stating that the draft final report had been sent to all concerned Accredited Representatives.

### Final Report

On 15 March 2025, CAAP released the final report on the accident, which lists three primary causes of the incident. (All three happened on the second approach that resulted in another go around before the final third touchdown) 1) Pilot's forward pitch control resulting in ground contact before the runway. 2) Increase in vertical wind factor. 3) Right hand main landing gear hit a 15cm step of the cement edge of runway 22 resulting in damage to the landing gear and subsequent loss of most of the deceleration means. The contributory cause factors were threefold. 1) Loss of spoilers and reversers. 2) Aircraft brake system failure. 3) Deficiency in Airbus' crew operating procedure and alerting in relation to blue hydraulic low-level fault.