PANGKALAN BUN, Indonesia - Search and rescue officials say they believe the main fuselage of AirAsia Flight 8501 has been located on the Java Sea floor, some 1.7 nautical miles east of the spot where the tail was recovered.

A ship from Indonesia's navy was on-scene Tuesday, assessing options on how to get the wreckage to the surface.

Retrieval of that part of the plane is considered vital. The director of operations of Indonesia's search and rescue agency, S. B. Supriyadi, predicts at least half the bodies of the 162 people who perished in the December 28 crash could be inside. So far, 48 bodies have been recovered.

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Decomposition is making identification more difficult for desperate families waiting to bury their loved ones. Nearly all passengers and crew were Indonesian. Officials have said returning all the bodies to loved ones remains a priority.

The word on the fuselage came on the same day divers retrieved the jetliner's second "black box" from the seabed, giving investigators essential tools to piece together what brought Flight 8501 down.

The cockpit voice recorder was freed from beneath the heavy ruins of a wing early in the morning from a depth of about 98 feet, a day after the aircraft's flight data recorder was recovered, said Tonny Budiono, sea navigation director at the Transportation Ministry.

"Thank God," he said. "This is good news for investigators to reveal the cause of the plane crash."

The device will be flown to the capital, Jakarta, to be downloaded and analyzed with the other box. Since it records in a two-hour loop, all discussions between the captain and co-pilot should be available.

The plane crashed 42 minutes into a flight from Surabaya, Indonesia, to Singapore on Dec. 28.

The find is the latest boost in the slow-moving hunt to scour the shallow, murky stretch of ocean.

The tail of the Airbus A320 was recovered over the weekend, emblazoned with the carrier's red-and-white cursive logo. The black boxes are housed inside the tail, but were missing when the wreckage was pulled to the surface.

The devices were soon located after three Indonesian ships detected two strong pings being emitted from their beacons, about 22 yards apart. Strong currents, large waves and blinding silt have hindered divers' efforts throughout the 17-day search, but they took advantage of calmer early morning conditions on both days to extract the instruments.

The information pulled from the black boxes - which are actually orange - will likely be crucial. Designed to survive extreme heat and pressure, they should provide investigators with a second-by-second timeline of the flight.

The voice recorder captures all conversations between the pilots and with air traffic controllers, as well as any noises heard in the cockpit, including possible alarms or explosions. The flight data recorder saves information on the position and condition of almost every major part in the plane, including altitude, airspeed, direction, engine thrust, the rate of ascent or descent and what up-or-down angle the plane was pointed.

"There's like 200-plus parameters they record," said aviation expert John Goglia, a former U.S. National Transportation Safety Board member. "It's going to provide us an ocean of material."

In their last contact with air-traffic controllers, the pilots of the AirAsia jet asked to climb from 32,000 feet to 38,000 feet to avoid threatening clouds, but were denied permission because of heavy air traffic. Four minutes later, the plane dropped off the radar. No distress signal was received.