Crash of a Pacific Aerospace PAC 750XL near Oksibil: 8 killed

Date & Time: Aug 11, 2018 at 1420 LT
Operator:
Registration:
PK-HVQ
Survivors:
Yes
Site:
Schedule:
Tanah Merah – Oksibil
MSN:
144
YOM:
2009
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
7
Pax fatalities:
Other fatalities:
Total fatalities:
8
Captain / Total flying hours:
13665
Captain / Total hours on type:
1468.00
Aircraft flight hours:
4574
Aircraft flight cycles:
5227
Circumstances:
On 11 August 2018, a PAC 750XL aircraft registered PK-HVQ was being operated by PT. Marta Buana Abadi (Dimonim Air) on unscheduled passenger flight from Tanah Merah to Oksibil. At the day of the occurrence the meteorological condition at Oksibil was below the requirement of Visual Flight Rule (VFR) weather minima and did not improve. Being aware that some flights had performed flight to Tanah Merah to Oksibil and returned, the pilot decided to fly to Oksibil. At 1342 LT, on daylight condition the PK-HVQ aircraft departed from Tanah Merah to Oksibil, on board the aircraft were one pilot, one observer pilot and 7 passengers. According to the passenger and cargo manifest, the total weight of passenger and the baggage were 473 kg. Prior to the departure, there was no record or report of aircraft system malfunction. At 1411 LT, the PK-HVQ pilot made initial contact to Oksibil Tower controller and reported that the aircraft was maintaining altitude of 7,000 feet over and the estimate time arrival at Oksibil would be 0520 UTC (1420 LT). The Oksibil Tower controller advised the pilot of the latest meteorological condition that the visibility was 1 up to 2 km and most of the area were covered by cloud. At 1416 LT, the pilot reported that the aircraft position was over Oksibil Aiport and the Oksibil Tower controller instructed the pilot to continue the flight to the final runway 11 and to report when the runway had in sight. The Oksibil Tower controller and pilots of other aircraft called the pilot but no reply. On the following day, the aircraft was found on a ridge of mountain about 3.8 Nm north west of Oksibil on bearing 331° with elevation about 6,800 feet. Eight occupants were fatally injured and one occupant was seriously injured.
Probable cause:
The KNKT concluded the contributing factors as follows:
- The VFR weather minimum requirement that was not implemented properly most likely had made the pilot did not have a clear visual to the surrounding area.
- Considering that the Pilot in Command (PIC) had lack knowledge of the terrain surrounding the Oksibil area, and the absence of voice alert from the TAWS when the aircraft flying close to terrain, resulted in the PIC did not have adequate awareness to the surrounding terrain while flying into clouds and continued to fly below the terrain height until the aircraft impacted the terrain.
Final Report:

Crash of a Cessna 208 Caravan I near Oksibil: 1 killed

Date & Time: Apr 12, 2017 at 1240 LT
Type of aircraft:
Operator:
Registration:
PK-FSO
Flight Phase:
Flight Type:
Survivors:
No
Site:
Schedule:
Tanah Merah – Oksibil
MSN:
208-0313
YOM:
1999
Country:
Region:
Crew on board:
1
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
4236
Captain / Total hours on type:
2552.00
Aircraft flight hours:
6226
Aircraft flight cycles:
9371
Circumstances:
On 12 April 2017, a Cessna C208 aircraft registered PK-FSO was being operated by PT. Spirit Avia Sentosa (FlyingSAS) for unscheduled cargo flight. The flights of the day scheduled for the aircraft were Mopah Airport (WAKK) – Tanah Merah Airport (WAKT) – Oksibil Airport (WAJO) – Tanah Merah – Oksibil – Tanah Merah. The estimated time departure of first flight from Mopah Airport to Tanah Merah was 0800 LT and the flight departed at 0848 LT, on board the aircraft were two pilots and seven passengers. The aircraft arrived in Tanah Merah at about 0943 LT. At 1012 LT, the flight departed from Tanah Merah to Oksibil. About 10 Nm from Oksibil the pilot contacted the Oksibil tower controller to get air traffic services and landed at 1044 LT. The flight then departed from Oksibil to Tanah Merah at 1058 LT and arrived about 1126 LT. These flights were single pilot operation. At 1144 LT on daylight condition, the aircraft departed Tanah Merah with intended cruising altitude of 7,000 feet. Prior to departure, there was no report or record of aircraft system malfunction. On board the aircraft was one pilot, 1,225 kg of general cargo and 800 pounds of fuel which was sufficient for about 3 hours of flight time. After departure, the pilot advised Tanah Merah tower controller of the estimate time arrival at Oksibil would be 1224 LT. At 1149 LT, the pilot advised Tanah Merah tower controller that the aircraft position was about 10 Nm from Tanah Merah and passing altitude of 3,500 feet. The Tanah Merah tower controller acknowledged the message and advised the pilot to monitor radio communication on frequency 122.7 MHz for traffic monitoring. At about 29 Nm from Oksibil, the PK-FSO aircraft passed a Cessna 208B aircraft which was flying on opposite direction from Oksibil to Tanah Merah at altitude 6,000 feet. At this time, the aircraft ground speed recorded on the flight following system was about 164 knots. The Cessna 208B pilot advised to the pilot on radio frequency 122.7 MHz that the PK-FSO aircraft was in sight. The pilot responded that the aircraft was maintaining 7,000 feet on direct route to Oksibil. At 1230 LT, the Oksibil tower controller received phone call from the FlyingSAS officer at Jakarta which confirming whether the PK-FSO aircraft has landed on Oksibil. The Oksibil tower controller responded that there was no communication with the PK-FSO pilot. The Oksibil tower controller did not receive the flight plan for the second flight of the PK-FSO flight. Afterwards, the Oksibil tower controller called Tanah Merah tower controller confirming the PK-FSO flight and was informed that PK-FSO departed Tanah Merah to Oksibil at 1144 LT and the reported estimate time of arrival Oksibil was 1224 LT. At 1240 LT, the Oksibil tower controller received another phone call from the FlyingSAS officer at Jakarta which informed that the FlyingSAS flight following system received SOS signal (emergency signal) from PK-FSO aircraft and the last position recorded was on coordinate 04°48’47.7” S; 140°39’31.7” E which located approximately 6 Nm north of Oksibil. Afterwards, the Oksibil air traffic controller advised the occurrence to the Search and Rescue Agency. On 13 April 2017, at 0711 LT, the PK-FSO aircraft was found on ridge of Anem Mountain which located about 7 Nm north of Oksibil. The following figure showed the illustration of the aircraft track plotted on the Google earth refer to the known coordinates of Tanah Merah, Oksibil and the crash site.
Probable cause:
The possibility of the pilot being fatigue, physical and environment condition increased pilot sleepiness which might have made the pilot inadvertently falling asleep indicated by no pilot activity. The absence of GA-EGPWS aural alert and warning was unable to wake up the pilot.
Final Report:

Crash of an ATR42-300 near Oksibil: 54 killed

Date & Time: Aug 16, 2015 at 1455 LT
Type of aircraft:
Operator:
Registration:
PK-YRN
Flight Phase:
Survivors:
No
Site:
Schedule:
Jayapura - Oksibil
MSN:
102
YOM:
1988
Flight number:
TGN267
Country:
Region:
Crew on board:
4
Crew fatalities:
Pax on board:
50
Pax fatalities:
Other fatalities:
Total fatalities:
54
Captain / Total flying hours:
25287
Captain / Total hours on type:
7340.00
Copilot / Total flying hours:
3818
Copilot / Total hours on type:
2640
Aircraft flight hours:
50133
Aircraft flight cycles:
55663
Circumstances:
An ATR 42-300 aircraft registered PK-YRN was being operated by PT Trigana Air Service on 16 August 2015 as scheduled passenger flight with flight number IL267 from Sentani to Oksibil. On board of this flight were 54 persons. This flight was the fifth flight of the day and the second flight from Sentani to Oksibil. The aircraft departed Sentani at 0522 UTC and estimated time of arrival Oksibil was at 0604 UTC. The Second in Command (SIC) acted as Pilot Flying while the Pilot in Command (PIC) acted as Pilot Monitoring. The weather at Oksibil reported that the cloud was broken (more than half area of the sky covered by cloud) and the cloud base was 8,000 feet (4,000 feet above airport elevation) and the visibility was 4 up to 5 km. The area of final approach path was covered by clouds. The flight cruising at 11,500 feet and at 0555 UTC, the pilot made first contact with Oksibil Aerodrome Flight Information Services (AFIS) officer, reported on descent at position Abmisibil and intended to direct left base leg runway 11. At 0600 UTC, Oksibil AFIS officer expected the aircraft would have been on final but the pilot had not reported, the AFIS officer contacted the pilot but did not reply. The AFIS officer informed Trigana in Sentani that they had lost contact with IL267. The aircraft wreckage was found on a ridge of Tanggo Mountain, Okbape District, Oksibil at approximately 8,300 feet AMSL at coordinates of 04°49’17.34” S, 140°29’51.18” E, approximately 10 NM from Oksibil Aerodrome on bearing of 306°. All occupants were fatally injured and the aircraft was destroyed by impact force and post impact fire. The Flight Data Recorder (FDR) and Cockpit Voice Recorder were recovered and transported to KNKT recorder facility. The recovery of FDR data was unsuccessful while the recovery of CVR data successfully retrieved accident flight data. The CVR did not record any crew briefing, checklist reading not EGPWS warning prior to impact. The CVR also did not record EGPWS altitude call out on two previous flights. The investigation concluded that the EGPWS was probably not functioning.
Probable cause:
The following findings were identified:
1. The aircraft had valid Certificate of Airworthiness and was operated within the weight and balance envelope.
2. All crew had valid licenses and medical certificates.
3. The flight plan form was filed with intention to fly under Instrument Flight Rule (IFR), at flight level 155, with route from Sentani to MELAM via airways W66 then to Oksibil. The MORA of W66 between Sentani to MELAM was 18,500 feet.
4. The flight was the 5th flight of the day for the crew with the same aircraft and the second flight on the same route of Sentani to Oksibil.
5. The CVR data revealed that the previous flight from Sentani to Oksibil the flight cruised at altitude of 11,500 feet and the approach was conducted by direct to left base runway 11.
6. The CVR data also revealed that on the accident flight, the flight cruised at altitude 11,500 feet and intended to direct left base leg runway 11 which was deviate from the operator visual guidance approach that described the procedure to fly overhead the airport prior to approach to runway 11.
7. The witness stated that most of the time, the flight crew deviated from the operator visual approach guidance. The deviation did not identify by the aircraft operator.
8. The downloading process to retrieve data from the FDR was unsuccessful due to the damage of the FDR unit that most likely did not record data during the accident flight. The repetition problems of the FDR unit showed that the aircraft operator surveillance to the repair station was not effective.
9. The CVR did not record any crew briefing, checklist reading and EGPWS altitude callout prior to land on two previous flights nor the EGPWS caution and warning prior to impact.
10. The spectrum analysis of the CVR determined that both engines were operating prior to the impact.
11. Several pilots, had behavior of pulling the EGPWS CB to eliminate the nuisance of EGPWS warning. The pilots stated that the reason for pulling the EGPWS CB was due to the pilots considered this warning activation was not appropriate for the flight conditions. The correction to this behavior was not performed prior to the accident.
12. The investigation could not determine the actual EGPWS CB position during the accident flight.
13. The installation of EGPWS by the aircraft operator was not conducted according to the Service Bulletin issued by the aircraft manufacturer.
14. The terrain data base installed in the EGPWS of PK-YRN was the version MK_VIII_Worldwide_Ver_471 that was released in 2014. The Oksibil Airport was not included in the high-resolution update in this version of terrain database.
15. The information for Oksibil published in AIP volume IV (Aerodrome for Light Aircraft/ALA) did not include approach guidance. The operator issued visual guidance of circling approach runway 11 for internal use.
16. The visual approach guidance chart stated that the minimum safe altitude was 8,000 feet while the aircraft impacted with terrain at approximately 8,300 feet. This indicated an incorrect information in the chart. The investigation considered that the pattern on the approach guidance chart was not easy to fly, as many altitudes and heading changes.
17. Several maintenance records such as component status installed on the aircraft and installation of EGPWS was not well documented. This indicated that the maintenance management was not well performed.
18. The investigation could not find any regulation that describes the pilot training requirement for any addition or modification of aircraft system which affect to the aircraft operation.
19. There was no information related to the status of ZX NDB published on NOTAM prior to the accident.
20. Several safety issues indicated that the organization oversight of the aircraft operator by the regulator was not well implemented.
Contributing Factors:
1. The deviation from the visual approach guidance in visual flight rules without considering the weather and terrain condition, with no or limited visual reference to the terrain resulted in the aircraft flew to terrain.
2. The absence of EGPWS warning to alert the crew of the immediate hazardous situation led to the crew did not aware of the situation.
Final Report:

Crash of a De Havilland DHC-6 Twin Otter 300 near Oksibil: 15 killed

Date & Time: Aug 2, 2009 at 1100 LT
Operator:
Registration:
PK-NVC
Flight Phase:
Survivors:
No
Site:
Schedule:
Jayapura - Oksibil
MSN:
626
YOM:
1979
Flight number:
MZ9760D
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
12
Pax fatalities:
Other fatalities:
Total fatalities:
15
Captain / Total flying hours:
8387
Captain / Total hours on type:
8387.00
Copilot / Total flying hours:
1207
Copilot / Total hours on type:
1207
Aircraft flight hours:
27336
Circumstances:
On the morning of Sunday, 2 August 2009, a de Havilland DHC-6 Twin Otter aircraft, registered PK-NVC, operated by PT. Merpati Nusantara Airlines as flight number MZ-7960D, departed from Sentani Airport, Jayapura for Oksibil Airport. The flight was planned in accordance with the visual flight rules (VFR). There were 15 persons on board; two pilots, one engineer, 10 adult passengers and two infants. The estimated flight time was 50 minutes. The fuel on board was sufficient for 2 hours and 50 minutes flight time. About 15 minutes prior to the estimated time of arrival at Oksibil the crew of another aircraft informed the Twin Otter crew that the weather in the Oksibil area was partly cloudy. There were no further reports of radio transmissions from the Twin Otter, and it did not arrive at Oksibil. A search was initiated at the time the aircraft would have run out of fuel. On the morning of 4 August 2009, searchers located the wreckage of the Twin Otter at an elevation of about 9,300 feet about 6 Nm from Oksibil. The aircraft was destroyed by impact forces, and all of the occupants were fatally injured.
Probable cause:
The pilots did not maintain visual flight procedures when flying below lowest safe altitude, and the aircraft was flown into cloud in the vicinity of gap north west of Oksibil. In conclusion, the accident was consistent with controlled flight into terrain.
Final Report:

Crash of a Piper PA-31-350 Navajo Chieftain in Papua: 2 killed

Date & Time: Nov 19, 1994
Operator:
Registration:
PK-IWC
Flight Phase:
Flight Type:
Survivors:
No
Site:
Schedule:
Jayapura - Oksibil
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
2
Circumstances:
The crew departed Jayapura-Sentani Airport on a cargo flight to Oksibil. En route, the twin engine aircraft disappeared, maybe in a mountainous area located north of Oksibil. The wreckage was never found.