Trigana Air Flight 267
Trigana Air Flight 267 was a scheduled passenger flight from Sentani to Oksibil in the eastern Indonesian province of Papua. On 16 August 2015, the ATR 42 turboprop operating the service crashed on approach in the Bintang highlands region of Oksibil, killing all 49 passengers and 5 crew members.
With 54 deaths, it is the deadliest accident involving the ATR 42, and the airline's deadliest accident since its establishment in 1991.
The Indonesian National Transportation Safety Committee published its final report into the accident in December 2017.
Deviation from visual approach guidance and visual flight rules without regard to weather and terrain, and the likely deactivation of the EGPWS system contributed directly to the crash, compounded by shortcomings in Trigana Air's safety culture.
Flight
The Trigana Air flight took off from Sentani Airport in Jayapura at 14:22 WIT and was scheduled to land in Oksibil at about 15:16. Oksibil is a remote town near the country's border with Papua New Guinea. Oksibil Airport did not have an instrument landing system to guide aircraft in to land because it is located close to a mountain.Contact was lost with the aircraft at about 14:55. There was no indication that a distress call was made by the crew. The crew had been expected to make contact with ground staff at Oksibil Airport at around 15:00; attempts by those at the airport to contact the aircraft were unsuccessful. At the time of the accident, the aircraft was on the final section of its scheduled route.
Weather conditions
Conflicting statements regarding the weather conditions were released. Stormy weather was initially cited as a possible cause of the crash, however it was later confirmed that the weather was good. Minister of Transportation Ignasius Jonan stated that bad weather was not the cause of the crash. Data from the local Indonesian Agency for Meteorology, Climatology and Geophysics office showed that the weather at the time of the crash was sunny. The crew of another aircraft landing prior to the crash also reported conditions at the time as "good".Several pilots stated that flying was difficult in the region. A pilot, Captain Andhy Gunawan, stated that the terrain in Papua was very dangerous and warned that the weather conditions in the area are also dangerous, as visibility could be limited. The Ministry of Transportation acknowledged that Indonesia's air navigation system equipment was very outdated and dated back to the 1950s, especially in remote areas such as Papua. Most airports in Papua did not have modern navigation aids at the time. Without this equipment, the airports and flight crew must conduct operations under instrument flight rules and rely on visual flight rules. This however could turn out to be dangerous as Papua's weather was "unforgiving and unpredictable" with most airports not receiving reports about weather condition in the area.
Search
At 15:30, Indonesia's National Search and Rescue Agency deployed a search aircraft to find the missing ATR 42. The search was suspended due to foggy weather and was resumed, with several additional search aircraft augmented by a search team on foot, on 17 August. Local residents contacted police and reported that they saw the aircraft crash into the Tangok Mountain in the Okbape district of Pegunungan Bintang Regency. Airborne searchers spotted the wreckage about from Oksibil. The Indonesia Transportation Ministry confirmed that the wreckage was located at an elevation of. All 54 passengers and crew were found to have died. The terrain itself had never been previously explored by humans, according to BASARNAS officials.Recovery
BASARNAS sent 250 personnel to Oksibil in response to the crash. Due to the thin air at this high altitude rescuers were unable to use air transport to recover victims or wreckage, necessitating an overland recovery. The terrain itself is described as "very steep". It took around three days to reach the wreckage on foot, or six hours by vehicle. Indonesian National Police sent three Disaster Victim Identification teams into the area to identify the victims of the crash. The bodies will be transported to a military hospital in Jayapura. However, bad weather and low visibility hamper the search and rescue effort. Weather systems around the wreckage were "unpredictable", according to BASARNAS. The identification of the victims will use DNA, tooth samples and forensic DNA analysis from surviving family members. The families have sent post-mortem and ante-mortem data to the police.By 18 August 2015 all of the dead had been found, but bad weather prevented the recovery of victims' bodies. Some victims' bodies were intact and exhibited burn injuries, others were mutilated and difficult to be identified. Photos taken from the crash site reveal that the aircraft had been heavily fragmented into smaller pieces by the force of the impact with no chance of survival. By nightfall on 19 August seventeen bodies had been carried out from the crash site. Initial reports that both flight recorders had been found in good condition were later contradicted, as authorities revealed on 19 August that the flight data recorder was still missing. The Flight Data Recorder was eventually found on 20 August and shown to media.
Aircraft and operator
The ATR 42 aircraft was registered PK-YRN, it was manufactured in 1988 and originally operated in the United States before being transferred to Trigana Air in 2005. The airline operated five more of the same aircraft type and three aircraft of the larger ATR 72 variant at the time of the crash.Aircraft operated by Trigana Air were involved in fourteen serious accidents between 1992 and 2016, eleven of which resulted in hull loss.
Passengers and crew
The aircraft was carrying 49 passengers and 5 crew members. The passenger manifest released by Trigana Air indicated all on board were Indonesian. There were 44 adults, 3 children and 2 infants among the passengers. There were two pilots; Captain Hasanuddin had joined Trigana in 2000, he had 25,200 hours of total flying experience and 7,300 hours' experience flying ATR 42s. First Officer Aryadin Falani had joined Trigana in 2008 and had a total of 3,800 hours flying experience, of which 2,600 were in flying ATR 42s. Both of them were described by Trigana as very experienced pilots.Among the passengers were four postal servicemen heading to Oksibil to distribute the Indonesia Sejahtera card, a programme for the poor that President Joko Widodo developed and promoted while campaigning for the 2014 Indonesia Presidential Election. They were reportedly carrying around 6.5 billion rupiah. Three local government officials and two members of the Regional Representatives Council were also on board to attend celebrations in Oksibil for the 70th anniversary of Indonesia's independence.
Investigation
The Indonesian National Transportation Safety Committee opened an investigation to the crash. In line with international regulations, as the aircraft was built in France, its Bureau d'Enquêtes et d'Analyses pour la Sécurité de l'Aviation Civile participated, sending three investigators. Aircraft manufacturer ATR also assisted and sent four technical advisers.The flight manifest released by Trigana was found to be wrong, being for another Trigana flight. As a result, the Chairman of Sentani Airport was fired by the Transportation Ministry. Sixteen workers were also investigated by the police because of their involvement. Two of Trigana's staff remained in custody. Ignasius Jonan, Indonesian Minister of Transportation, criticized the airport staff saying the situation was a "big mess" and needed to be cleaned up.
Investigators rebuilt the predicted flight path of Flight 267, using Google Earth and data from the CVR and its spectrum analysis. They noted that the Flight Data Recorder was unusable. The analysis of the CVR revealed that at 14:55 local time, the flight crew of Flight 267 stated their intention to make a direct left base. Immediately after that, Flight 267 deviated from its predicted flight path.
Flight 267 deviated to the right. The area on the right side of Flight 267 was surrounded by mountainous terrain. Some of the terrain was as high as 8,000 ft. In addition, Papua's unpredictable weather would endanger the flight easily. Pilots have reported that fogs sometimes "came out of nowhere", which could limit the pilot's visibility. Though good condition was reported in the area, there were also localized fogs in the mountains. According to the NTSC, based on the CVR analysis, Flight 267 entered clouds and fogs. The altitude of Flight 267 was not sufficient enough to pass the mountains. The mountains were covered by fog at the time. It is plausible that their proximity to terrain was not noticed by them.
The investigation team decided to investigate the crew's motivation to deviate from the flight's predicted flight path. They checked on the crew's previous flight from Sentani to Oksibil. It was revealed that the crew did exactly the same thing: making a direct left base by deviating from its predicted flight path. Investigators then stated that the crew might have been overconfident with their flying skill. Similar to TransAsia Airways Flight 222, due to their previous success on landing an aircraft prior to the accident, the crew believed that they were able to do the same thing in the future without considering the consequences. The crew had accrued thousands of flight hours and were familiar with the airport. Because of their familiarity with the terrain, they tend to be confident with their skill. Thus, their situational awareness were reduced significantly.
However, these were all preventable had the EGPWS sounded and warned the crew of their proximity to terrain. The NTSC noted that the EGPWS didn't sound at all during the flight's final moment, even though Flight 267 was going to hit the mountain. Investigators revealed that the circuit breaker which was responsible for the activation of the EGPWS had been pulled off by Flight 267's crew. Similar to the Mount Salak Sukhoi Superjet tragedy, the crew had shut down the EGPWS warning on purpose. Trigana Air's management personnel stated that some pilots had stated that the warnings sometimes sounded during inappropriate condition. This led some pilots to think that the EGPWS had malfunctioned. Thus, the EGPWS was de-activated by pulling the circuit breaker. The management had identified some pilots including the accident pilot of the pilot with behaviour of pulling the EGPWS's circuit breaker.
As per the final report, the investigation concludes that the EGPWS power supply circuit
breaker was pulled during the accident flight and the two previous flights, explaining the absence of altitude call out during the two previous approaches and warning prior to the impact. Further investigation revealed that Trigana Air had published an approach chart with wrong information to the pilot. The approach chart stated that the minimum safe altitude was at 8,000 ft. Flight 267 impacted the mountain at 8,300 ft. The NTSC considered the approach chart as wrong, ineffective and hard to understand. Aircraft maintenance was also badly performed by the airline.
The final report concluded that the accident was a controlled flight into terrain that was caused by the crew's decision to deviate from its projected flight path. The absence of EGPWS warnings aggravated the condition.
Aftermath
Mourning
The aircraft crashed one day before Indonesia celebrated its 70th anniversary; Indonesian President Joko Widodo urged all Indonesians to pray, and held a minute of silence in order to remember the victims. Crisis centres were set up in Sentani and Jakarta. BASARNAS also set up three crisis centres in Jayapura. Minister of Transportation Ignasius Jonan commented that Trigana Air "must treat the affected families as well as possible". Shortly after the crash, flowers and condolence banners were displayed in front of Trigana Air's head office. The condolences came from various airlines, including Sriwijaya Air, Aviastar and head staff of INACA.Trigana Air stated it would pay compensation as it claimed responsibility for the crash, with a total of Rp.1,25 billion in compensation for each person killed in the crash. Jasa Raharja was also to also pay compensation of Rp. 100 million for each person, bringing the total to Rp. 1,35 billion.
Infrastructure
Indonesia's People's Representative Council urged the government to upgrade the air navigation system at every airport in Indonesia. The Indonesian government stated that it would work with AirNav Indonesia to upgrade the infrastructure in Papua.There were twelve small airports slated for upgrade by the government. Among them were Sumenep Airport, Labuan Bajo Airport and Oksibil Airport. The first phase is the upgrade of the information system transferring data from Aeronautical Flight Information Services to Area Aerodrome Control towers. Updated weather reports would also be issued by the local weather station more frequently. The safety procedures upgrade process was to take around six months, and the ADC towers upgrade about a year. Some runways at the airports were also to be upgraded.
Andrew Herdman, head of the Association of Asia Pacific Airlines said:
More resources are needed but of course governments face many demands on their resources. Further investment is needed in infrastructure. Many of the airports in Indonesia are dealing with congestion well beyond their design capacity. Some of the smaller airports, and this most recent tragedy involved short haul service between two remote airports in inhospitable terrain in Papua -- airports in that terrain need upgrading of navigation aids and other operational enhancements.