Because of broken parts in the first black box, investigators failed to retrieve all information.
Indonesian divers hunted on Friday for a second black box from an aircraft that crashed into the sea this week with the loss of all 189 people on board, as investigators tried to get data from a partly damaged recorder already found.
The Lion Air Boeing Co 737 MAX, which only went into service in August, crashed on Monday into the Java Sea.
Air traffic control lost contact with it 13 minutes after it took off from the capital, Jakarta, heading north to the tin-mining town of Pangkal Pinang.
Searchers have found one black box and just one passenger has been identified from partial human remains recovered from the shallow waters.
"We haven't downloaded the data because there are some broken parts in the black box," Haryo Satmiko, the deputy of the transport safety panel, said of the flight data recorder found on Thursday, adding that some of the damage was to a socket on the device.
Satimiko told Reuters investigators were awaiting advice from the U.S. National Transportation Safety Board or Boeing.
The pilot of flight JT610 had asked for, and received, permission to turn back to Jakarta airport, but what went wrong remains a mystery.
Efforts are now focused on retrieving the second of the two black boxes, as the cockpit voice recorder and the flight data recorder are known, the head of Indonesia's transport safety committee said.
"The team have been hearing the 'ping' sound from another black box for two days," Soerjanto Tjahjono told Reuters.
The sea is only 30 m (98 ft) deep at the crash site but strong currents and nearby energy pipelines have hampered the search for the aircraft operated by the budget carrier.
While victims' relatives are desperate to know what happened, the investigation of the first crash of a Boeing 737 MAX is also the focus of scrutiny by the global aviation industry.
Investigators said the damage suffered by the first data device reflected the severity of the impact.
Downloading the data on flight recorders can take as little as two hours but analysing it can take weeks.
Results of a preliminary investigation will be made public after 30 days, one official on the investigation team said.
President Joko Widodo, visiting the search operation's headquarters at Jakarta's port, thanked rescue officials and the military involved and appealed for them to step up the search.
"I ask for you to use all your might, all the technology available, to work fast to find anything else," he said.
He said he wanted investigators to determine the cause of the crash quickly so "we can determine the next step".
Relatives of the missing have been looking through personal items recovered from the sea including rows of shoes, backpacks and wallets.
Television footage showed an aircraft wheel being hoisted from the sea on Friday and a diver holding a piece of what appeared to be part of the fuselage bearing the Lion Air logo.
The search and rescue agency said that 65 body bags with human remains had been taken to a police hospital where forensic doctors have been trying to identify victims.
Doctors have been taking DNA samples from relatives.
Indonesia is one of the world's fastest-growing aviation markets but its safety record has been patchy. Its transport safety panel investigated 137 serious aviation incidents from 2012 to 2017.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)Source Article