Sriwijaya Air Flight 182

Sriwijaya Air Flight 182 was a scheduled domestic passenger flight operated by Sriwijaya Air from Soekarno–Hatta International Airport, Tangerang, to Supadio International Airport, Pontianak, West Kalimantan. On 9 January 2021, the Boeing 737–524 disappeared from radar four minutes after departure. Officials confirmed that the aircraft crashed in the waters off the Thousand Islands, some 19 km from the airport.

Based on reports from local fishermen in the area, the search for the aircraft was immediately initiated. Although wreckage, human remains, and clothing had been found, the search for the full aircraft and all passengers is still ongoing. The position of the cockpit voice and flight data recorder has been located by Indonesian authorities.

Flight timeline
Prior to Flight 182, the aircraft arrived at 12:11 PM from Pangkal Pinang Depati Amir Airport. The aircraft was scheduled to take off from Soekarno–Hatta International Airport in Tangerang, Banten, at 13:25 WIB (06:25 UTC), and was scheduled to arrive at Supadio International Airport in Pontianak, West Kalimantan, at 15:00 WIB (08:00 UTC). After pushing back from the airport's Terminal 2D, the aircraft took off from Runway 25R at 14:36 local time (07:36 UTC). The flight took off amid heavy monsoon rain, following a bad weather delay. Due to the significant delay, it was expected to land in Pontianak at 15:50 WIB (08:50 UTC).

Flight 182 was climbing to 13000 ft when it abruptly dived, then it suddenly turned to the right. An air traffic controller (ATC) noticed this and asked the pilots, but received no response. According to AirNav Radarbox flight data, the aircraft reported a rapid drop in altitude during the climb phase from 10900 ft to 7650 ft at 07:40 UTC. Flightradar24 reported that four minutes after takeoff, the aircraft dropped by 10000 ft in less than a minute. The flight tracker also noted that the last recorded altitude of the aircraft was 250 feet (76 m) at 07:40:27 UTC. According to provided flight data, the plane experienced a drop of 1755 ft in just six seconds between 07:40:08 and 07:40:14 UTC. It was followed by a drop of 825 ft in two seconds, 2725 ft in four seconds, and 5150 ft in its last seven seconds. During the fall, the aircraft rapidly changed speed, decreasing and increasing in seconds. Its last contact with ATC was at 14:40 WIB (07:40 UTC). The aircraft is presumed to have crashed into the Java Sea near Laki Island and 19 km from Soekarno–Hatta International Airport. According to the ATC, there was no distress call during the flight. Indonesian transport officials also stated that the aircraft failed to follow ATC instructions.

Aircraft
The aircraft involved was a Boeing 737-524, registered as PK-CLC (MSN 27323/2616). It was equipped with two CFMI CFM56-3B1 engines. As of 19 March 2012, it flew for 45,359 hours on 24,306 flights.

The aircraft was manufactured in 1994, had its maiden flight on 13 May 1994. It was first delivered to Continental Airlines the same year on 31 May under the registration N27610. The aircraft was transferred to United Airlines in 2010 after Continental and United merged. On 15 May 2012, the aircraft was sold to Sriwijaya Air. It was the first of a total of fifteen 737-500s received by Sriwijaya Air in 2012 to replace their 737-200s. Sriwijaya Air named the aircraft Citra. Between 23 March and 23 October 2020, the aircraft was stored at Surabaya Juanda International Airport for repair, before resuming back to service on 19 December.

The aircraft has a moderate accident record. On 29 October 1994, a bird strike occurred, with the bird ingested in one of the engines. On 4 November 2004, another bird hit the fuselage on approach to Austin, Texas' Bergstrom International Airport. The following year on 12 July, a gull hit the left side of the radome fuselage, whilst on approach to Raleigh, North Carolina's Durham International Airport.

Passengers and crew
There were 62 people on board, of which 50 were passengers. Of the remaining 12 crew members, six were operating crew on the flight, while the other six were transported to another location as passengers. All are thought to have been Indonesians. Among the passengers was Mulyadi Tamsir, a politician from Indonesia's People's Conscience Party (Hanura Party, or Partai Hati Nurani Rakyat).

The active crew consisted of Captain Afwan, First Officer Diego Mamahit and four flight attendants. Afwan was a former pilot in the Indonesian Air Force.

The aircraft was also carrying 500 kg of freight.

Search and rescue
Several eyewitness accounts were reported. A local fisherman reported that part of the aircraft crashed just 14 m from his location. He stated that the aircraft exploded in mid-air and a piece of the aircraft that was on fire fell to the sea, with "shards of a kind of plywood" almost hitting his ship. Meanwhile, citizens of the Thousand Islands, near where the plane crashed, heard two explosions. It was raining in the area at the time. The first report of a plane crash in the Thousand Islands was made at 14:30 local time (07:30 UTC), in which a fisherman stated that a plane had crashed and exploded in the sea. At around 16:00 local time (09:00 UTC), eyewitnesses coordinated with firefighters to search for the aircraft. Junaedi, the Regent of Thousand Islands, also reported that something fell and exploded on Laki Island.

9 January
Air Marshal Bagus Puruhito, the head of the Indonesian National Search and Rescue Agency (BASARNAS), reported that the crash site was located 11 nmi from Soekarno-Hatta International Airport. Personnel from a vessel provided by the Ministry of Transportation reported that body parts, fragments of clothing, electronics, personal belongings and wreckage had been recovered from the sea in waters near the Thousand Islands, with aviation fuel also reported around the location. The water near the likely crash site has a depth of around 15-16 m. BASARNAS immediately deployed personnel to the crash site while the Indonesian National Police and the Ministry of Transportation set up crisis centers in Port of Tanjung Priok and Soekarno–Hatta International Airport respectively. The Indonesian Navy deployed a number of vessels for the SAR operations, in addition to helicopters and KOPASKA (frogman) personnel.

The Indonesian National Transportation Safety Committee (NTSC) reported that it will send a research ship to assist in the search and rescue operation. The vessel had been previously involved in search and rescue operations of multiple aviation accidents, including Lion Air Flight 610 and Indonesia AirAsia Flight 8501 which crashed into the Java Sea as well. Meanwhile, the Indonesian Navy deployed seven ships and divers from the 1st Naval Regional Command to assist the search and rescue process. Soon after, BASARNAS reported that the pings of the aircraft's Emergency Locator Transmitter (ELT) had not been detected. The exact crash location was later announced to the public. At the same time, the Indonesian Red Cross deployed 50 volunteers and prepared at least 100 body bags for the victims of the accident. Family members of the victims were asked to bring DNA samples and other antemortem information to the Disaster Victims Identification unit at Kramat Jati Hospital in Jakarta. Accommodations for relatives were provided by Sriwijaya Air.

On the night of 9 January 2021, an emergency slide of the aircraft was recovered from the waters near Lancang Island, Thousand Islands. Several other pieces of wreckage were recovered from the crash site; the search and rescue operation was hampered by low visibility.

10 January
On 10 January 2021, Minister of Transportation Budi Karya Sumadi alongside with the Commander of the Indonesian National Armed Forces Hadi Tjahjanto supervised the search and rescue operation on board the KRI John Lie.

The Indonesian Navy announced that three different methods would be used during the search operation. It would also examine any contrast in the sea and sonar would also be used. The Navy later reported that based on the findings on sea water contrast, several pieces were detected near the South Laju Island. Sea water contrast also showed a "very clear" evidence of aviation fuel. The Indonesian Navy announced that the exact coordinates of the crash site have been pinpointed. The Indonesian Armed Forces stated that 4 teams of divers will be deployed to the site, while the Indonesian Navy will deploy 150 personnel and helicopters to the crash site. At 03:00 WIB, the diving team of KOPASKA dived into the sea in search for remnants from the flight. The Indonesian National Police soon sent 1 aircraft, 4 helicopters, 8 boats and 50 divers to the crash site. A total of 192 personnel from the police force were deployed to assist the search and rescue operation. In total, as of 10 January 2021, more than 10 ships have been tasked to search for the aircraft.

The search and rescue operation initially had to be halted due to deteriorating weather condition. However, once it improved, the search and rescue operation was resumed.

At 08:00 WIB (01:00 UTC), police received a bag of body parts; they were later transported to Kramat Jati Hospital. More human remains, as well as life jackets from the aircraft, were also found. Later in the afternoon, more remains and wreckage were recovered from the crash site. Rescuers managed to recover a life vest, pieces from the aircraft's fuselage and a destroyed wheel rim of the Boeing 737. Most of the wreckage was found at a depth of 17 - 23 m. Parts of the hydraulic system of the Boeing 737-524, seating number and a part from the registration code of the aircraft had been recovered from the crash site. The scattered debris and the small pieces of the wreckage indicated a high-speed impact. The Indonesian National Armed Forces stated that the main focus has now shifted to find the main body of the aircraft. The Indonesian Air Force also said that it had spotted a fuel spill, suspected to be from the aircraft, covering a very large part of the sea, south of Laki island. Among debris recovered, on the morning of 10 January 2021, were parts of the plane's wheels, a torn steel alloy sheet with blue paint and pink children's jacket and trousers.

By the night of 10 January 2021, BASARNAS had recovered at least 16 large aircraft parts from the crash site, including one of the aircraft's turbines. At least 10 body parts had also been recovered. BASARNAS later reported that the research vessel KRI Rigel had detected pings from the aircraft's flight recorders. The pings were located at 200 metres between each other. On the same day, NTSC confirmed that multiple debris had been identified, including the aircraft's door, GPWS, radio altimeter and some part from the aircraft's empennage.

The NTSC reported they have located the position of both black boxes and divers will start looking for them.

11 January
As of 11 January, some 2,600 personnel were involved in the search operation, with more than 50 ships and 13 aircraft searching for the wreckage. A heavy rainstorm hampered the work of divers. The team utilized the Triangle Method: the search area was narrowed to a triangle. Four ships, of the Garuda Jaya class, equipped with special tools to make the search easier, were planned to be used the next day if necessary. The search area was also widened. Meanwhile, BASARNAS discovered additional 27 human remains, confirmed to be from victims of the flight.

The first identification of a body part was achieved by the police using the Indonesia Automatic Finger Print Identification System (INAFIS). The victim's identity was later confirmed as Ocky Bisma, the male flight attendant.

Investigation
The NTSC was immediately notified of the accident, with assistance from BASARNAS. NTSC stated that, starting on 10 January 2021, just before 06:00 local time, search and rescue personnel would start searching for the aircraft's flight recorders. It added that the investigation will be assisted by the United States' National Transportation Safety Board (NTSB).

A spokeswoman from the Indonesian Ministry of Transportation reported that an abnormality was noted during the flight. The aircraft departed from Jakarta's Soekarno-Hatta International Airport on a standard instrument departure. The aircraft had been cleared to climb to 29000 ft. During its climb, Flight 182 went off course to the northwest. ATC asked the crew about the deviation and got no response. A few seconds later, the aircraft dropped off radar.

The director of Sriwijaya Air said that the aircraft was airworthy. Although a 30-minute delay was noted, he insisted that the cause was bad weather, specifically heavy rain, rather than mechanical failure. In response, the NTSC said that they would be coordinating with the Meteorology, Climatology, and Geophysical Agency (BMKG) in relation to weather in the Jakartan area.

An Indonesian aviation expert said that based on the preliminary data retrieved from the aircraft, Flight 182 might have suffered a sudden failure that happened "so fast that pilots couldn't do anything." He stated the aircraft had been stored for repairs by Sriwijaya Air between 23 March and 23 October 2020, signifying good maintenance history.

On 10 January 2021, NTSC obtained raw data of the aircraft's flight path from radar and interviews with the air traffic controller. Investigators also retrieved the transcript of the communication between the pilots and the ATC.

An investigator with NTSC stated that based on the distribution of the debris, the aircraft possibly ruptured when it hit the water.

Weather
Analysis by the Indonesian National Institute of Aeronautics and Space (LAPAN) showed that extreme weather conditions were not present during the crash. Satellite images retrieved by the institute did not show any abnormal weather condition at the time of the accident. LAPAN stated that a meso-convective system had been formed near the Java Sea at 11:00 local time (04:00 UTC), but the system had already dissipated by the time Flight 182 took off. Weather data retrieved from BMKG confirmed the presence of moderate to heavy precipitation with thunder reported. The data later showed that a 15 km high cumulonimbus cloud was present around Soekarno-Hatta International Airport with the minimum temperature of the cloud tops at -70 C, prompting speculation that the aircraft had encountered turbulence. Visibility was reported to be 2 km.

Responses
In the immediate aftermath of the accident, the state's insurance company Jasa Raharja announced that it would compensate the relatives of the passengers and crew members aboard Flight 182. Each next-of-kin of the deceased would receive 50 million rupiah (US$). The Indonesian National Police prepared several policewomen for trauma healing for the relatives of the victims.