An aerial search for victims and wreckage of a crashed Indonesian plane has expanded as divers continued combing the debris-littered seabed looking for the cockpit voice recorder.

The National Search and Rescue Agency had temporarily suspended the search for the second black box on Wednesday due to bad weather and waves up to five metres high.

The Boeing 737-500 disappeared on Saturday minutes after taking off from Jakarta with 62 people aboard.

One black box containing flight data was recovered on Tuesday, and the hundreds of search personnel have also recovered plane parts from the Sriwijaya Air service and human remains from the Java Sea.

Indonesian navy personnel inspect a part the flight data recorder recovered at the crash site of the Sriwijaya Air flight
Indonesian navy personnel inspect a part the flight data recorder recovered at the crash site of the Sriwijaya Air flight (Fadlan Syam/AP)

The aerial search is being expanded to coastal areas of the Thousand Island chain “because plane debris and victims may be carried away by sea currents,” said Rasman, the agency’s search and rescue mission coordinator who goes by a single name.

Navy officials have said the two black boxes were buried in seabed mud under tons of wreckage between Lancang and Laki islands in the Thousand Island chain north of Jakarta.

At least 268 divers were deployed on Thursday, almost double the previous figure.

Rescuers increased to 4,100 personnel, supported by 13 helicopters, 55 ships and 18 raft boats.

So far, the searchers have sent 141 body bags containing human remains to police identification experts.

Families have been providing DNA samples to the disaster victim identification unit, which, on Wednesday, said it had identified six victims, including a flight attendant and an off-duty pilot.

Indonesian National Transportation Safety Committee (KNKT) investigators have inspected debris
Indonesian National Transportation Safety Committee (KNKT) investigators have inspected debris (Achmad Ibrahim/AP)

The airline’s data showed both pilots in command of the plane were highly experienced and had relatively good safety records.

Captain Afwan, who also goes by one name, began his career as an air force Hercules pilot and had several decades of flying experience. He was known to his relatives and friends as a devout Muslim and preacher.

Afwan’s co-pilot, Diego Mamahit, was equally qualified.

Nurcahyo Utomo, an investigator with Indonesia’s National Transportation Safety Committee, known by its Indonesian acronym as KNKT, said the crew did not declare an emergency or report technical problems before the plane nosedived into the sea.

He said investigators are now working to read critical details on the flight data recorder that was salvaged earlier and tracks electronic information such as airspeed, altitude and vertical acceleration.

Investigators and experts from the US National Transportation Safety Board, the jet engine producer General Electric and Boeing will be joining the investigation in the next few days.