What happened
On 15 August 2008, a China Airlines A340-300, registration B18802, was performing a scheduled international flight from Taoyuan International Airport to Incheon International Airport. While approaching runway 34, the aircraft encountered heavy precipitation.
During the landing phase, the aircraft touched down on the runway, but the crew struggled to maintain the centerline due to rapidly deteriorating visibility. The first officer noted a drift to the right, and although a go-around was initiated, the aircraft ran off the runway onto the grass approximately 1,000 feet from the threshold. The excursion caused the aircraft to strike runway facilities, resulting in a 15 cm rupture and denting to the lower left surface of the aft fuselage. There were no injuries to the 232 passengers or the crew.
The investigation
The ARAIB investigation examined the flight data, cockpit voice recordings, and meteorological conditions at the time of the incident. Investigators analyzed the aircraft's performance during the touchdown and the effectiveness of the communication between the tower and the flight crew. The investigation also reviewed the operation of the airport's lighting systems and the visibility information provided by the air traffic controller.
Findings
- The primary cause of the runway excursion was that an instant go-around was not performed until visual references of the runway were no longer positively confirmed.
- The approach lighting and runway lights for runway 34 were not activated prior to the aircraft's arrival, which hindered the crew's ability to visually confirm the runway.
- The crew did not strictly adhere to the airline's manual regarding autopilot use during adverse weather conditions.
- While the aircraft's weather radar identified heavy precipitation, this information was not effectively utilized to adjust the landing approach.
- The air traffic controller did not activate the approach lights due to a lack of immediate visibility of the decreasing runway visual range on the control panel.
Safety action
Following the investigation, the ARAIB issued safety recommendations to China Airlines to improve pilot training regarding adverse weather and stricter adherence to missed approach principles. Recommendations were also made to the Ministry of Land, Transport and Maritime Affairs to improve the visibility of weather radar displays for controllers and to implement an alerting system for the activation of aeronautical lighting.