What happened
On 2 October 2008, a Boeing 737-4K5, registration PK-GWT, was operating a scheduled passenger flight from Jakarta to Palembang. The flight crew, which included a training captain and a candidate captain acting as pilot flying, was conducting a VOR/DME approach to runway 29. At the time, the airport's Instrument Landing System (ILS) was out of service for maintenance.
During the final approach, the aircraft drifted from the intended flight path. While the crew reported seeing the runway, the aircraft actually descended below the Minimum Descend Altitude (MDA) and touched down on a parallel taxiway rather than the active runway. The pilots realized the error upon seeing barriers on the taxiway, prompting the captain to apply manual brakes. The aircraft came to a stop approximately 700 meters from the point of impact. There were no injuries among the 49 passengers and 6 crew members on board, though the aircraft sustained damage to a main-wheel tyre.
The investigation
The investigation focused on the flight path accuracy, crew performance, and airport infrastructure. Investigators found that the VOR/DME approach track was misaligned with the actual runway centerline by approximately 200 meters due to a 2-degree difference between the approach track and the runway direction.
Furthermore, the investigation examined the presence of old runway markings on the parallel taxiway, which had been used as a temporary runway during previous airport construction. These markings were still visible and could be mistaken for runway touchdown zones. The investigation also reviewed the role of Air Traffic Control (ATC), noting that while the controller observed the deviation, standard procedures only permitted a go-around command if the runway itself was deemed unsafe.
Findings
- The primary cause of the incident was a misalignment of the VOR approach path relative to the runway centerline.
- The flight crew was overly focused on internal cockpit instruments and failed to sufficiently cross-check the external environment once visual references were established.
- The pilot monitoring did not adequately monitor the aircraft's position relative to the runway.
- Residual runway markings on the parallel taxiway contributed to the visual confusion during the landing phase.
- ATC procedures limited the controller's ability to intervene unless a specific hazard was present on the runway.
Safety action
Following the incident, Palembang Airport Management implemented several measures, including painting taxiway markings black to prevent confusion and ensuring runway lights remain active during approaches. The NTSC also recommended that the airline improve Crew Resource Management (CRM) and pilot awareness regarding external scanning during the final approach phase.