Indonesian authorities are planning to issue a preliminary report on the investigation into the crash of Lion Air Flight JT610 by the end of the month, on November 28-29, 2018. Despite having retrieved the plane’s flight data recorder a few days after the nearly new Boeing 737 MAX 8 crashed into the sea on October 29, 2018, investigators say finding the second black box, the cockpit voice recorder, will be critical in determining the cause of the crash.

Indonesia’s Transportation Safety Committee (KNKT), which is leading the investigation into the October 29, 2018, crash, says they have now downloaded information from the Boeing 737 MAX’s flight data recorder, but have not been able to determine the whereabouts of the cockpit voice recorder.

“From the black box data, we know about 70-80 percent of what happened but to 100-percent understand the cause of the accident... we need be able to know the conversation that took place in the plane’s cockpit,” Soearjanto Tjahjono, the head of KNKT, told Reuters. Authorities have not commented on what the data from the first black box had revealed.

Investigators believe the missing cockpit voice recorder may have been damaged on impact, because they have not yet detected any “ping” signals that would indicate its location, the way it did with the first black box, which was found just days after the crash. According to Tjahjono, authorities are searching for 15 aircraft parts, including the “angle of attack” (AOA) sensor.

Meanwhile, Indonesia’s National Search and Rescue agency (Basarnas) has declared the end of the search for the victims of the crashed Boeing 737 MAX, when it plunged into the sea just 13 minutes after taking off from Jakarta, killing all 189 people on board.

“There is nowhere left to search and we have stopped finding victims’ bodies,” Muhammad Syaugi, the head of Basarnas, was quoted as saying in an earlier report by Reuters. “We will limit our operations to monitoring.”

Out of at least 196 body bags containing human remains retrieved from the sea as of November 10, 2018, a total of 79 victims have been identified forensic examination; they comprising the remains of 59 men and 20 women, an update from Lion Air states.