Black box recovered from the wreckage of sunken Lion Air Flight JT610.Indonesian navy divers on Thursday (Nov 1) recovered the black box of downed Lion Air flight JT610 which holds vital clues on what caused Indonesia’s worst aviation disaster in two decades.
The navy team located the device at a depth of around 30 meters in waters northeast of the Indonesian capital, Jakarta. On Wednesday, search teams had heard pings from a locating beacon attached to the data recorder, but strong ocean currents stopped them from recovering the device.
All 189 people on board the Boeing 737 Max 8 plane are feared dead after it crashed into Java Sea shortly after take-off on Monday morning.
“We followed the device, and narrowed the area (of search) and then we dug again the location where the sensitive (ping) sound was heard and finally found the blackbox,” said diver Hendra Saputra, who found the black box.
There are two so-called black boxes on each plane, and they are actually bright orange. One records conversations in the cockpit, while the other tracks crucial data like airspeed, altitude, and fuel flow. The one recovered on Thursday is the flight data recorder, Transportation Minister Budi Karya Sumadi said. 
The search for black boxes normally takes days and even weeks.
The black boxes of Air Asia QZ8501, which plunged into the Java Sea en route from Surabaya to Singapore on Dec 24, 2014, and killed 162 people on board, were found after 16 days of search.
Basarnas chief Muhammad Syaugi told reporters earlier that the search on Thursday morning will focus on sector four of the search area that is divided into 13 sectors.
“(Sector four) is the area where we detected what we suspect is a body part of the plane. And also where we picked up the ‘ping’,” he said, referring to the sound emitting from the black boxes and picked up by underwater “pinger locators”.
The search area has been doubled in size to cover a 10-nautical-mile-radius area with the center located at the point where the plane lost contact with air traffic controllers shortly after take-off on Monday morning.
Retrieving the black box will be key to an ongoing investigation into the cause of Monday’s crash, one of the worst in the country’s aviation history.
The head of Indonesia’s national search and rescue agency Basarnas meanwhile told reporters that apart from the black box, divers also found a large object measuring 1.5m by 0.5m that could be part of the fuselage.
The biggest question following the crash, the first for Boeing 737 Max 8, is why a plane that started flying just two months ago could have crashed.
Speculation about what caused the crash has centered on possible problems with the plane’s transmission of airspeed data. The day before the crash, the same plane had experienced unreliable airspeed readings, which could have been the result of a malfunction of instruments that measure data needed to fly the plane.
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Data from flight-tracking sites showed the plane was unstable during the first minutes of its second-last flight, showing erratic speeds, altitude and direction just after take off.
Mr Budi, the transport minister, said his team has checked all Boeing 737 Max 8 aircraft in the fleet operated by Lion Air and found no technical problem.
“But, our evaluation will be forwarded to the KNKT and we will also discuss it with the Boeing team,” he told a press conference, referring to Indonesia’s National Transportation Safety Committee (KNKT). He added that a more detailed assessment of the aircraft will be conducted.
KNKT chief Soerjanto Tjahjono said on Thursday his team will meet representatives from the aircraft manufacturer Boeing and the US National Transportation Safety Board who have arrived in Jakarta to help out with the investigation, which KNKT says would take up to six months.
“The aircraft is a new type. So we need much explanation from the manufacturer,” he told reporters in a Kompas TV broadcast.
The national search and rescue agency Basarnas operational director Bambang Suryo Aji on Monday ruled out the possibility that the plane exploded in mid-air, as the debris and human remain found showed no signs of being burnt.
Syaugi told Elshinta radio on Thursday morning that the search teams will have a better chance of recovering the black boxes on Thursday after they received the go-ahead from state oil company Pertamina to throw an anchor to stabilise the main search and rescue vessel.
“Yesterday afternoon, the currents were strong. We had to throw an anchor, but we only had clearance to do so last night from Pertamina. The sea floor there is lined with Pertamina pipes,” head of the national search and rescue agency (Basarnas) Muhammad Syaugi told Elshinta radio on Thursday morning.
