Landing with a bump at Taipei Taoyuan International Airport during Tropical Cyclone Kong-rey

4 November 2024

Leung Yan Yu Christy, Kok Mang Hin Marco

A Starlux Airline JX871 departed Okinawa on 31 October 2024 and was originally scheduled to arrive Taipei at 08:20 UTC. In the same afternoon, Tropical Cyclone Kong-rey made landfall over Taitung province and the associated high winds and convective clouds affected most parts of Taiwan. Due to low visibilities and significant wind shear conditions at the Taipei Taoyuan International Airport (TPE), the aircraft had entered into a hold before making its final approach (Figure 1). The aircraft made its first attempt to land at 09:34 UTC, but bounced upon touching the runway and leaned towards the left with its wingtip nearly touched the runway (Video 1). The pilot then decided to go around. In the second landing attempt, the aircraft landed successfully.

Figure 1: Flight path of JX871 arriving Taipei (Data source: RadarBox)

Video 1: The first and second landing attempts of JX871 (Source: ShanghaiEye YouTube channel)

Meteorological Aerodrome Report (METAR) is the routine weather report describing the meteorological elements observed at an airport at a specific time. METARs* of TPE in the evening on 31 October 2024 given below indicated that gale force winds with gusts up to storm force were registered about the time of the first landing attempt.

METAR of TPE on 2024/10/31, 09:30 UTC and 10:00UTC

METAR RCTP 310930Z 08039G55KT 9999 -SHRA FEW010 SCT025 BKN080 27/25 Q0986 WS ALL RWY NOSIG RMK A2914=
METAR RCTP 311000Z 08044G58KT 9999 -SHRA FEW010 SCT025 BKN120 27/25 Q0986 WS ALL RWY NOSIG RMK QFF 986.4HPA A2913 RA AMT 0.2MM=

*For decoding of METARs, readers may refer to the following link.

To assess the impact of high winds on landing aircrafts, it is crucial to consider the crosswinds near the touch down zone. Crosswind is wind blowing from the side of aircraft. Large changes in crosswind during landing might cause an aircraft to deviate from the runway centerline. Crosswinds over 25 knots are deemed significant, and pilots may "crab" (pointing the aircraft towards the wind so that the aircraft heading forms an angle with the runway alignment) or “wind-low” (adding a small rolling angle such that the two wings are not on the same levels) to counter balance the effect of crosswinds. For the JX871 case, the aircraft was landing onto runway 05R with a mean crosswind of around 20 to 22 knots and crosswind gusts between 27 to 29 knots. The significant crosswind and gusts blowing across the runway may have contributed to the incident, causing the aircraft leaned towards its left side.

At the Hong Kong International Airport (HKIA), the runways are oriented in the directions of about 70 degrees and 250 degrees from magnetic north. High winds from the north or south may produce significant crosswinds along runways (Figure 2). The issuance of tropical cyclone signals by Hong Kong Observatory mainly consider the overall wind speed observed and forecast over Hong Kong, but whether aircraft can take off or land would largely depend on the magnitude of crosswind (see “Can Aircraft Take-off and Land at the Hong Kong International Airport under the Influence of a Tropical Cyclone?”). Therefore, not only wind speed, the wind direction is also crucial to aircraft operations.

Figure 2: Schematic diagram of crosswind at the runways of HKIA

When a tropical cyclone approach Hong Kong and pose an impact to air traffic at HKIA, the Hong Kong Observatory (HKO) will conduct special weather briefings for the aviation community at HKIA with the latest assessment of weather forecast, including the forecast of crosswind. Additionally, HKO will also issue wind shear and turbulence alerts and warnings for the aviation community utilising the network of detection systems installed around the HKIA, including the Terminal Doppler Weather Radar, Light Detection and Ranging (LIDAR) systems, wind profilers and a dense network of surface wind sensors. If, unfortunately, you are flying from or to an airport that might be affected by tropical cyclones, please be advised to check with the airlines for the latest flight information before travelling to the airport.