Aircraft and Crew
The accident aircraft was a British Aerospace BAe 146-300, registered PK-BRD, operated by PT. Aviastar Mandiri Airlines on a scheduled passenger and cargo flight. The crew consisted of two pilots, two flight attendants, an engineer, and a load master.
Flight Description
On the morning of 9 April 2009, the aircraft was flying from Sentani Airport to Wamena Airport, Papua. The crew performed a go-around from the initial landing approach on runway 15 at Wamena. The flight crew then positioned the aircraft on a right downwind leg for another landing approach. As the aircraft turned towards the final approach for the second landing approach, it impacted terrain and was destroyed.
Investigation Findings
The Enhanced Ground Proximity Warning System (EGPWS) manufacturer conducted simulations using flight recorder data and two terrain data sources. The manufacturer stated that “the GPWS/EGPWS alerts recorded in the CVR were issued as designed”. However, the enhanced Look-Ahead function appeared to have been inhibited following the go-around. The cockpit voice recorder (CVR) showed no evidence that the crew deliberately inhibited the terrain function of the EGPWS. The investigation determined that the EGPWS issued appropriate warnings in GPWS mode. The pilot in command did not take appropriate remedial action in response to repeated EGPWS warnings.
Conclusions and Safety Actions
The investigation concluded that the flight crew’s lack of awareness of the aircraft’s proximity with terrain, together with non-conformance to the operator’s published operating procedures, resulted in the aircraft’s impact with terrain. As a consequence, the operator took safety action to address deficiencies in documentation for missed approach procedures at Wamena. The National Transportation Safety Committee (NTSC) issued safety recommendations to the operator and the Directorate General Civil Aviation (DGCA) to ensure implementation of relevant documented procedures. Additionally, safety issues concerning aircraft modification and DGCA approval were identified, which did not contribute to the accident but were considered safety deficiencies. The NTSC report included recommendations to address those issues.