“There’s a mud sucker that works like a vacuum cleaner,” said Soerjanto Tjahjono, chief of the National Transportation Safety Committee. “We extracted the mud down to one meter deep. Last night, when it was the last night of the search, we found it.”
A preliminary crash investigation by the committee, which was based in part on information from the data recorder and maintenance records, concluded last month that a difference in the level of thrust between the plane’s two engines might have contributed to the aircraft rolling over before it plunged into the sea.
A difference in the level of thrust — the force of the engines that propels the aircraft forward — can make planes difficult to control, but it is unclear why that problem may have occurred during the Sriwijaya flight.
Officials hope that the recovered memory module will shed some light on why the pilot and co-pilot were unable to recover control of the plane, which plummeted more than 10,000 feet in less than a minute.
“Without the cockpit voice recorder, it would be very difficult to know the cause in this Sriwijaya 182 case,” Mr. Soerjanto said.
The Sriwijaya aircraft was the third to crash into the Java Sea in just over six years after departing from airports on Java, one of Indonesia’s five main islands.
In December 2014, Air Asia Flight 8501 crashed into the Java Sea off the coast of Borneo with 162 people aboard as it flew from the Indonesian city of Surabaya to Singapore. Investigators eventually attributed the disaster to the failure of a key component on the Airbus A320-200 and an improper response by the flight crew.