What happened
On August 21, 2003, at 11:59 local time, a Far Eastern Air Transport flight, operating an MD-82 with registration B-2/8011, landed at Kinmen Shangyi Airport. The flight had originated from Taipei Songshan Airport and was carrying 152 people, including 146 passengers and 6 crew members.
During the final phase of the approach, the flight crew encountered unstable conditions. To correct a slightly high altitude, the pilot increased the descent rate, which subsequently increased the aircraft's speed beyond the company's recommended stable approach criteria. Despite this, the crew decided to continue the landing rather than performing a go-around. The aircraft touched down 2,366 feet from the threshold of Runway 06, with a speed 27 knots higher than the reference speed (Vref).
Following touchdown, the aircraft began to veer left. As the crew applied maximum reverse thrust to decelerate on the wet and slippery runway, the aircraft's directional control was lost. The aircraft eventually veered off the left side of the runway, coming to a stop on the clearways near the threshold of Runway 24. There were no fatalities and no injuries, though the aircraft sustained minor damage.
The investigation
The investigation examined the meteorological conditions, the flight crew's performance, and the technical aspects of the aircraft's handling. Investigators found that the Kinmen area was experiencing unstable weather characterized by drizzling rain and significant wind gusts.
Technical analysis of the MD-82 revealed that when reverse thrust exceeds 1.3 EPR, aerodynamic forces on the vertical stabilizer and rudders are significantly reduced. At levels exceeding 1.6 EPR, these surfaces have almost no effect on directional control. The investigation established that the crew's use of maximum reverse thrust, intended to prevent a runway excursion, actually contributed to the loss of steering.
Furthermore, the investigation identified discrepancies in the airline's training and manuals. The company's stable approach criteria were not clearly defined for abnormal descent rates, and the phraseology used by the pilot monitor to alert the pilot flying was not standardized, hindering effective communication during the critical approach phase.
Findings
- The primary cause of the excursion was the unstable approach, characterized by an excessive descent rate and touchdown speed significantly higher than Vref.
- The use of maximum reverse thrust by the crew caused a loss of directional control due to the aerodynamic interference with the rudder and vertical stabilizer.
- High-speed touchdown on a wet, slippery runway increased the required landing distance by approximately 34%, significantly raising the risk of excursion.
- A lack of standardized phraseology between the pilot flying and pilot monitor prevented effective decision-making regarding a necessary go-around.
- The aircraft was operating using Jeppesen charts that had not yet been updated to reflect the most recent aeronautical information published by the CAA.