A problem with the Boeing 737-500's autothrottle system was reported after a flight a few days earlier, says National Transportation Safety Committee investigator Nurcayho Utomo.
Indonesia’s air accident investigator has launched an investigation into whether a problem with Sriwijaya Air flight autothrottle system, which controls engine power automatically, contributed to the crash on January 9 that killed all 62 people on board.
National Transportation Safety Committee (KNKT) investigator Nurcayho Utomo said on Friday a problem with the Boeing 737-500's auto throttle system was reported after a flight a few days earlier.
"There was a report of malfunction on the autothrottle a couple of days before to the technician in the maintenance log, but we do not know what kind of problem," he told Reuters. "If we find the CVR (cockpit voice recorder) we can hear the discussion between the pilots, what they talked about and we will know what is the problem."
It remains unclear whether a problem with the autothrottle system contributed to the crash, Utomo said, adding he could not recall any other issues raised in the maintenance log.
It is acceptable for a plane to fly with an autothrottle system that is not working because pilots can control it manually instead, he said.
Sriwijaya said he was unable to comment on technical matters involving the investigation before an official statement was made by KNKT. A preliminary report is expected to be issued within 30 days of the crash, in line with international standards.
READ MORE: Indonesia recovers data from crashed Sriwijaya Air jet’s flight recorder
Broken autothrottle system
The plane's flight data recorder (FDR) has been recovered and read by investigators but an underwater search for the CVR's memory unit at the crash site in the Java Sea is continuing.
Citing sources close to the investigation, the Wall Street Journal (WSJ) on Thursday reported the FDR data showed the auto throttle system was not operating properly on one of the plane's engines as it climbed on departure from Jakarta.
Instead of shutting off the system, the FDR indicated the pilots tried to get the stuck throttle to function, the WSJ said. That could create significant differences in power between engines, making the jet harder to control.
READ MORE: Indonesia finds black box from crashed Sriwijaya Air plane
Relatives of plane's victims
Relatives of the crash victims on Friday prayed and threw flowers into the Java Sea where the Sriwijaya Air jet plunged into the water almost two weeks ago.
An Indonesian navy vessel took dozens of grieving relatives to the site. Many people wept as they prayed and cast flower petals into the water, and officials from the navy, the search and rescue agency, and Sriwijaya Air employees threw wreaths into the sea.
The airliner’s President Director Jefferson Irwin Jauwena hoped by visiting the location to help relatives accept what happened to their loved ones and ease their grief.
“We also do feel sad and lost ... we lost our crew, they were part of our beloved Sriwijaya Air big family,” he told reporters on board the navy ship. “I, personally, feel so devastated by this accident.”
The jet nosedived into the water minutes after taking off from Jakarta, the capital on January 9. Searchers have recovered plane parts and human remains from an area between Lancang and Laki islands in the Thousand Island chain.
READ MORE: Five things to know about aviation disasters