Indonesian rescuers have pulled out body parts, pieces of clothing and scraps of metal from the Java Sea, a day after a Boeing 737-500 plane with 62 people onboard crashed shortly after takeoff from Jakarta.
Officials were hopeful they were honing in on the wreckage of Sriwijaya Air Flight 182 after sonar equipment detected a signal from the aircraft.
Transportation Minister Budi Karya Sumadi told reporters that authorities have launched massive search efforts after identifying "the possible location of the crash site."
"These pieces were found by the SAR team between Lancang Island and Laki Island," National Search and Rescue Agency Bagus Puruhito said in a statement.
The Sriwijaya Air plane lost contact with air traffic controllers minutes after taking off from Indonesia's capital on a domestic flight on Saturday.
Transportation Minister Budi Karya Sumadi said Sriwijaya Air's Flight SJ182 was delayed for an hour before it took off at 2.36pm (local time).
The Boeing 737-500 disappeared from radar four minutes later, after the pilot contacted air traffic control to ascend to an altitude of 8,839 metres, he said.
The airline said in a statement that the plane was on an estimated 90-minute flight from Jakarta to Pontianak, the capital of West Kalimantan province on Indonesia's Borneo island.
The plane was carrying 50 passengers, including seven children.
There were also 12 crew members on board, all Indonesian nationals, including six extra crew for another trip.
Sumadi said a dozen vessels, including four warships, were deployed in a search-and-rescue operation centred between Lancang island and Laki island, part of the Thousand Islands chain just north of Jakarta.
Bambang Suryo Aji, the National Search and Rescue Agency's deputy head of operations and preparedness, said rescuers collected plane debris and clothes that were found by fishermen.
They handed the items over to the National Transportation Safety Committee for further investigation to determine whether they were from the missing plane.
A commander of one of the search-and-rescue ships who goes by a single name, Eko, said that fishermen found cables and pieces of metal in the water.
"The fishermen told us that they found them shortly after they heard an explosion like the sound of thunder," Eko was quoted by TVOne as saying, adding that aviation fuel was found in the location where the fishermen found the debris.
No radio beacon signal detected
Aji said no radio beacon signal had been detected from the 26-year-old plane. He said his agency was investigating why the plane's emergency locator transmitter, or ELT, was not transmitting a signal that could confirm whether it had crashed.
"The satellite system owned by neighbouring Australia also did not pick up on the ELT signal from the missing plane," Aji said.
‘We thought it was a bomb’
Solihin, 22, a fisherman from Lancang Island, said he and two other fishermen heard an explosion around 30 metres from them.
"We thought it was a bomb or a tsunami since after that we saw the big splash from the water after the explosion.
"It was raining heavily and the weather was so bad. So it is difficult to see around clearly. But we can see the splash and a big wave after the sounds. We were very shocked and directly saw the plane debris and the fuel around our boat.”
Tracking service Flightradar24 said on its Twitter feed that Flight SJ182 lost more than 10,000 feet (3,048 metres) of altitude in less than a minute, about four minutes after take-off.
Sriwijaya Air President Director Jefferson Irwin Jauwena said the plane was airworthy. He told reporters that the plane had previously flown to Pontianak and Pangkal Pinang city on the same day.
"Maintenance report said everything went well and airworthy," Jauwena told a news conference.
He said the plane was delayed due to bad weather, not because of any damage.
It was raining at Jakarta's Soekarno-Hatta International Airport when the plane took off for Pontianak, around 740 kilometres away.
Television footage showed relatives and friends of people aboard the plane weeping, praying and hugging each other as they waited at airports in Jakarta and Pontianak.
Chicago-based Boeing said on its Twitter feed that it was aware of the incident. It said it was closely monitoring the situation and "working to gather more information”.
The airline has had a solid safety record until now, with no onboard casualties in four incidents recorded on the Aviation Safety Network database, though a farmer was killed when a Boeing 737-200 left the runway in 2008 following a hydraulic problem.
Indonesia, the world's largest archipelago nation, with more than 260 million people, has been plagued by transportation accidents on land, sea and air because of overcrowding on ferries, ageing infrastructure and poorly enforced safety standards.
In October 2018, a Boeing 737 MAX 8 jet operated by Lion Air plunged into the Java Sea just minutes after taking off from Jakarta, killing all 189 people on board.
The plane involved in Saturday's incident did not have the automated flight-control system that played a role in the Lion Air crash and another crash of a 737 MAX 8 jet in Ethiopia five months later, leading to the grounding of the MAX 8 for 20 months.
The Lion Air crash was Indonesia's worst airline disaster since 1997, when 234 people were killed on a Garuda airlines flight near Medan on Sumatra island.
In December 2014, an AirAsia flight from the Indonesian city of Surabaya to Singapore plunged into the sea, killing 162 people.
Indonesian airlines were previously banned from flying to the United States and European Union for not meeting international safety standards. Both have since lifted the ban, citing improvement in aviation safety and greater compliance with international standards.
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