DHC 4 Caribou PK-SWW — 5 Nm east of Ilaga Pass, Papua

During the investigation, it was found that the CVR CAM channel was covered by the engine noise and the voice in the cockpit could not be heard. The other station communication and aircraft system alert or warning sound were not recorded in the CVR. The review to the wiring design found that the CVR wiring interconnection had caused in the improper CVR recording. The improper CVR recording was in…

The TAWS or EGPWS terrain database in Papua area mostly provided in low resolution. The low-resolution terrain database resulted in un-necessary caution or warning whenever the aircraft flies to the mountainous area even though the flight able to be conducted safely. The pilot tends to inhibit or deactivate the TAWS or EGPWS system to avoid the un-necessary caution or warning. The flight with inac…

The test result of the modification of the aircraft by the installation of CVR, TAWS or other system after the aircraft had been modified were not available. The absence of the modification test result made the successful installation and functionality of the systems could not be ascertained. The investigation found that the voice that should be recorded on the CAM channel was covered by engine no…

After completion of the modification, the investigation revealed that in the modified CVR wiring system of the aircraft, the microphones lines of the SIC, PIC and spare line, were directly hooked to the channel 1 (SIC), 2 (PIC) and 3 (spare) of CVR audio line respectively. As the result, the incoming audio communication and other audio which generated by the aircraft system were not accommodated i…

According to factual information and initial findings, the Komite Nasional Keselamatan Transportasi (KNKT) recommend to Perkumpulan Penerbangan Alfa Indonesia to comply the DGCA Safety Circular number SE.24 of 2016.

During the flight, the PIC communicated with another aircraft pilot stated that the aircraft ‘was diving’ which can be assumed that the aircraft was flying in the cloud. The CASR Part 91.155 Basic VFR Weather Minimums, restricts the pilot to maintain certain distance with the cloud during flying in VFR flight. Flying in the cloud during VFR flight reduces the pilot awareness to the surrounding te…

The TAWS or EGPWS terrain database in Papua area mostly provided in low resolution. The low-resolution terrain database resulted in un-necessary caution or warning whenever the aircraft flies to the mountainous area even though the flight able to be conducted safely. The pilot tends to inhibit or deactivate the TAWS or EGPWS system to avoid the un-necessary caution or warning. The flight with inac…

During the investigation, it was found that the CVR CAM channel was covered by the engine noise and the voice in the cockpit could not be heard. The other station communication and aircraft system alert or warning sound were not recorded in the CVR. The review to the wiring design found that the CVR wiring interconnection had caused in the improper CVR recording. The improper CVR recording was in…