Indonesia plane crash

The Boeing 737-500 with 50 passengers and 12 crew was headed on a domestic flight to Pontianak in West Kalimantan on Saturday before it disappeared from radar screens four minutes after take-off.

There were no clues yet as to what caused the crash, the first major air crash in Indonesia since 189 passengers and crew were killed in 2018 when a Lion Air Boeing 737 Max also plunged into the Java Sea soon after taking off from the same airport.

Pieces of wreckage were brought to Jakarta port by rescuers, including the plane’s altimeter radar, emergency chute and a piece that was suspected to have come off of the bottom part of the plane’s tail, Indonesia National Transport Safety Committee (KNKT) official Nurcahyo Utomo said.

One twisted piece of metal was painted in Sriwijaya Air’s blue and red colours. Authorities said they came from a depth of 23 metres (75 feet) near a group of islands off the Jakarta coast.

Indonesian authorities said they had also retrieved body parts and clothing.

The plane crashed during its climb, shortly after takeoff. Flight tracking data from Flightradar24 shows the aircraft climbed to around 10,900 feet (3,322 m) in a similar profile to previous flights, before drastically losing altitude and falling towards the sea.

Speed also appears to progress along a similar profile to previous flights until suddenly, a major change can be seen and the plane loses more than half of its velocity. A few moments later, speed increases drastically to 663 kph before contact is lost, according to ground speed data tracked by Flightradar24.

The Sriwijaya Air plane was a nearly 27-year-old Boeing 737-500, much older than Boeing’s problem-plagued 737 MAX model. Older 737 models are widely flown and do not have the stall-prevention system implicated in the MAX safety crisis.

“We are in contact with our airline customer and stand ready to support them during this difficult time,” Boeing said in a statement. “Our thoughts are with the crew, passengers, and their families.”

Founded in 2003, Jakarta-based Sriwijaya Air group flies largely within Indonesia’s sprawling archipelago. The budget airline had written off four of its 737s between 2008 and 2017 due to bad landings that resulted in runway overruns, according to aviation data firm Cirium. The 2008 accident led to one death and 14 injuries.

KNKT chief Soerjanto Tjahjono said the locations of Flight SJ 182’s two black boxes had been identified.

“Hopefully, we can retrieve them soon,” said military chief Hadi Tjahjanto, without giving an estimated timeframe.

Retrieving the cockpit voice recorder and flight data recorder can help determine the cause of the crash. A transport ministry spokeswoman said air traffic control had asked the pilot why the plane was heading northwest instead of on its expected flight path seconds before it disappeared.

Search teams were able to detect the signal emitted from the underwater locator beacons attached to the black boxes. The “pings” can be picked up by vessels using sonar equipment as they search for the devices and wreckage on the ocean floor.

Newer jets and their engines emit streams of data to help airlines plan maintenance. But neither the 737-500 nor its engines leave such a digital trace, industry experts say.

The crash comes at a sensitive time and place for Boeing after poor software contributed to crashes of the newer 737 MAX in Indonesia and Ethiopia. But the long service history of the model involved in Saturday’s crash, and its lack of similar software, mean design is seen less likely to be a key factor.