Indonesia search and rescue teams hunting for the wreck of an AirAsia passenger jet have detected pings in their efforts to find the black box recorders, Santoso Sayogo, an investigator at the National Transportation Safety Committee, told Reuters.
Indonesia AirAsia Flight QZ8501 vanished from radar screens on December 28 less than half way into a two-hour flight from Indonesia's second-biggest city of Surabaya to Singapore.
There were no survivors among the 162 people on board.
Indonesian search teams loaded lifting balloons on to helicopters on Friday ahead of an operation to raise the tail section of the jet, although Sayogo said it appeared that the black box was no longer in the tail and divers were confirming its position.
The tail was found on Wednesday, upturned on the sea bed about 30km from the plane's last known location at a depth of around 30 metres.
"For today's operations, we will use helicopters to carry the balloons that will assist in lifting the tail," Lt Col Penerbang Jhonson Hendrico Simatupang told Reuters.
He said the weather was fine on Friday morning.
"But we are expecting sudden changes later in the day," he said. "So we're taking advantage now and moving the balloons as fast as we can."