What happened
On July 14, 2006, at approximately 19:15 local time, Far Eastern Airlines flight EF066, an MD-83 with registration B-28031, was performing an ILS approach to Runway 10 at Taipei/Songshan International Airport. The flight originated from Hualien Airport and carried 57 occupants, all of whom were unharmed.
During the landing roll, the aircraft's right main gear drifted off the runway surface. Investigation of the ground tracks revealed that the aircraft deviated south of the runway at approximately 1,950 feet from the threshold, before re-entering the paved surface at approximately 3,600 feet. Upon post-landing inspection, significant amounts of grass and vegetation were found entangled in the right main landing gear and wheel well area.
The investigation
The investigation examined the aircraft's flight path, weather conditions, and cockpit operations. Analysis of the flight data and radar tracks confirmed that the aircraft maintained a stable approach and met all requirements for descent below the decision altitude (DA/MDA) and standard operating procedures. The investigation also reviewed the airport's lighting configuration and the weather conditions present during the approach.
Findings
- The primary cause of the excursion was that heavy rainfall increased during the night approach, significantly reducing the crew's external visibility. This prevented the crew from timely detecting and correcting the rightward drift of the aircraft.
- The aircraft encountered a large convective cell, approximately 1.5 km wide, moving east toward the airport, which caused heavy rain showers just before and during landing.
- At the time of the excursion, the crew was relying on runway edge lights for visual reference due to the degraded visibility.
- The aircraft's right main gear exited the runway surface approximately 6 seconds after touchdown while traveling at 106 knots, and returned to the runway surface approximately 10 seconds after touchdown at 61 knots.
- The crew's training, medical status, and fatigue levels were all found to be within regulatory requirements, with no evidence of impairment by drugs or alcohol.