What happened
On 13 October 2012, a Sriwijable Air Boeing 737-300, registration PK-CJT, was operating a scheduled passenger flight from Medan to Minangkabau International Airport (WIPT) in Padang, Indonesia. The flight carried 102 people, including 96 passengers and 6 crew members.
During the approach phase, the flight crew requested an ILS approach for runway 33. While navigating the descent, the crew performed an approach briefing using a photocopy of the instrument approach chart. However, critical information regarding the proximity of Tabing Airfield—which shares a similar runway orientation—was not clearly legible on the provided document.
As the aircraft established on the localizer, the pilot observed a runway at a 10-degree angle to the right. Believing the localizer was incorrect, the pilot transitioned to a visual approach and disconnected the autopilot. During this manual maneuver, the aircraft's descent rate increased to approximately 1,700 feet per minute, resulting in an unstabilized approach. The aircraft subsequently landed at Tabing Airfield rather than the intended destination. All passengers and crew disembarked safely without injury.
The investigation
The KNKT investigation examined the flight's navigation, the legibility of the approach charts, and the air traffic control environment. Investigators found that the crew had deviated from the normal route due to several turns required to avoid weather. Furthermore, the investigation noted that the tower controller's attention had shifted to an aircraft pushing back on the ground at the time the landing clearance was issued for the arriving flight.
Findings
- The unclear legibility of the black-and-white photocopy of the ILS approach chart prevented the crew from noticing vital warnings regarding the adjacent airfield.
- The crew failed to maintain a stabilized approach, characterized by an excessive rate of descent during the final stages of the landing.
- The pilot's awareness of the nearby Tabing Airfield was significantly reduced by the lack of clear information in the approach documentation.
- The air traffic controller did not provide a warning regarding the incorrect runway during the abnormal approach phase.
Safety action
Following the incident, Sriwijaya Air implemented several measures, including requirements for more thorough approach briefings and ensuring all flight documents are clearly readable. The airport operator at Minangkabau International Airport issued a NOTAM to warn pilots of the nearby runway at Tabing Airfield and updated ATC procedures to include a specific reporting point to alert pilots of the potential for runway confusion.