Crashed Sriwijaya Air jet had engine thrust imbalance – preliminary report

By Fransiska Nangoy and Bernadette Christina Munthe

JAKARTA (Reuters) – The Sriwijaya Air plane that crashed last month killing 62 people had an imbalance in engine thrust that eventually led the plane into a sharp roll and then a final dive into the sea, a preliminary report by investigators said on Wednesday.

When the 26-year-old Boeing Co 737-500 plane reached 8,150 feet (2,484 m) after take-off, the left engine throttle lever moved back while the right lever stayed in its original position, Indonesia’s National Transportation Safety Committee (KNKT) said in its report.

“We don’t know if it’s broken or not, but it’s an anomaly because the left moved far back, the right did not as though it was stuck,” KNKT investigator Nurcayho Utomo told reporters of the levers.

At about 10,900 feet, the autopilot disengaged and the plane rolled to the left more than 45 degrees and started its dive, according to the report.

The Sriwijaya accident is Indonesia’s third major airline crash in just over six years and has shone a spotlight on the country’s poor air safety record.

Starting with just one plane in 2003, Sriwijaya has become the country’s No.3 airline group, aided by its strategy of acquiring old planes at cheap prices and serving routes neglected by competitors.

There had been two prior problems reported with the auto throttle system that automatically controls engine power based on maintenance logs, but the issue was rectified on Jan. 5, four days before the crash, KNKT said.

A working auto throttle is not required for a plane to be dispatched as pilots can control the thrust levers manually with their hands.

Divers are still searching for the plane’s cockpit voice recorder which could help investigators understand the actions taken by the pilots, both of whom were experienced with 17,900 hours for the captain and 5,100 hours for the first officer.

The report highlighted the importance of upset recovery training for pilots and the recognition of repetitive plane defects, just over six years after an AirAsia Indonesia crash where those were among the issues raised.

KNKT said that following the crash Sriwijaya had taken safety actions including adding upset recovery training in its next pilot proficiency check and reminding engineers that repetitive defects must be handled in accordance with safety manuals.

The airline sent a memo to pilots reminding them to write detailed reports to help engineers troubleshoot problems.

The Directorate General of Civil Aviation also discussed the handling of repetitive problems and upset prevention and recovery training with other Indonesian operators after the crash, KNKT said.

Boeing said it would continue to support the investigation.

The preliminary report, as is standard, laid out factual information obtained to date but did not list the contributing factors to the crash. That will require further investigation.

Safety experts say most air accidents are caused by a combination of factors that can take months to establish. Under international standards, the final report is due within a year of the crash.

(Reporting by Fransiska Nangoy and Bernadette Christina Munthe; additional reporting by Agustinus Beo Da Costa and Gayatri Suroyo; writing by Jamie Freed; Editing by Gerry Doyle and Kim Coghill)

Indonesia halts search for victims of Sriwijaya Air crash

By Yuddy Cahya Budiman

JAKARTA (Reuters) – Indonesian authorities said on Thursday the search for victims of a plane crash that killed all 62 people on board had been halted, but the hunt would continue for the Sriwijaya Air jet’s cockpit voice recorder (CVR).

“Search operations have been closed, but we will continue to search for the CVR,” said Bagus Puruhito, who heads the country’s search and rescue agency.

He told reporters that the rescue team had collected more than 324 bags of body parts and plane parts.

Flight SJ 182 crashed into the Java Sea on Jan. 9 four minutes after take-off from Jakarta.

Divers last week retrieved from the seabed the other so-called black box, the flight data recorder, of the 26-year-old Boeing Co 737-500 jet.

The Sriwijaya crash was the biggest airline disaster in Indonesia since October 2018, when 189 people were killed onboard a Lion Air Boeing 737 MAX that also plunged into the Java Sea soon after take-off.

(Reporting by Yuddy Cahya; Writing by Fanny Potkin; Editing by Martin Petty)

Indonesia resumes search for victims, black box of crashed Sriwijaya jet

By Bernadette Christina Munthe and Agustinus Beo Da Costa

JAKARTA (Reuters) – Indonesian divers resumed a search on Thursday for the remains of 62 victims and the cockpit voice recorder from a Sriwijaya Air plane that plunged into the Java Sea soon after takeoff last weekend, officials said.

The search at the crash site of the Boeing 737-500, which was traveling from Jakarta to Pontianak, had been temporarily suspended on Wednesday after bad weather whipped up high waves.

A team of divers recovered one of the plane’s black boxes, the flight data recorder (FDR), from the seabed earlier this week and efforts were underway on Thursday to retrieve the cockpit voice recorder (CVR).

With the cause of the fatal crash of the nearly 27-year-old plane unclear, investigators will rely heavily on the black boxes to determine what caused it to lose control minutes after take-off.

Indonesia National Transportation Safety Committee (KNKT) head Soerjanto Tjahjono told Reuters the FDR information was still being processed and a preliminary report would be published within 30 days of the crash in line with international standards.

Tempo newspaper on Thursday reported the plane had experienced recurring problems with the autothrottle system that automatically controls the engine power settings since returning from storage last month. Sriwijaya did not respond immediately to a request for comment.

Tjahjono said if the autothrottle system was not working, the pilots could control the settings manually with their hands.

An airline pilot who was not authorized to speak publicly said it was considered acceptable for a plane to fly when the autothrottle system was not working, though it would increase the pilot workload and could prove distracting in an emergency situation.

Most air accidents are typically caused by a range of factors that can take months to establish, according to safety experts.

The Sriwijaya crash is the biggest airline disaster in Indonesia since 189 people were killed onboard a Lion Air Boeing 737 MAX that plunged into the Java Sea minutes after take-off in 2018.

(Additional reporting by Stanley Widianto in Jakarta and Jamie Freed in Sydney; Writing by Kate Lamb and Jamie Freed, Editing by Angus MacSwan)