Divers retrieve cockpit voice recorder of AirAsia jet

Divers retrieved the cockpit voice recorder from the wreck of an AirAsia passenger jet on Tuesday, according to an Indonesian transportation official. The cockpit voice recorder is a key piece of evidence for investigators attempting to determine the cause of the crash that killed 162 people.

Transportation Ministry official Tonny Budiono says the trapped cockpit voice recorder was freed from beneath the wing's heavy ruins early Tuesday from a depth of about 100 feet, a day after the aircraft's flight data recorder was recovered.

It 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 during the 42-minute journey should be available.

The Airbus A320-200 airliner lost contact with air traffic control in bad weather on Dec. 28, less than halfway into a two-hour flight from Indonesia's second-biggest city of Surabaya to Singapore. There were no survivors.

The black boxes contain a wealth of data that will be crucial for investigators piecing together the sequence of events that led to the airliner plunging into the sea.

The cockpit voice recorder will be flown to the capital, Jakarta, to be downloaded and analyzed with the other box. It could take up to two weeks to download and analyze their information, said Nurcahyo Utomo, an investigator at the National Committee for Safety Transportation.

Dozens of Indonesian navy divers took advantage of calmer weather this week to retrieve the black boxes and now hope to find the fuselage of the Airbus. Extreme weather has hampered the search.

Forty-eight bodies have been retrieved from the Java Sea and brought to Surabaya for identification. Searchers believe more bodies will be found in the plane's fuselage.

Based on past crashes, the information retrieved from the black boxes could be vital. The two separate devices — designed to survive extreme heat and pressure — should provide investigators with a second-by-second timeline of the plane's flight.

The voice recorder takes audio feeds from four microphones within the cockpit and records all the conversations between the pilots, air traffic controllers as well as any noises heard in the cockpit, including possible alarms or explosions.  

The flight data recorder captures 25 hours' worth of information on the position and condition of almost every major part in a plane. It includes a multitude of data, including altitude, airspeed, direction, engine thrust, the rate of ascent or descent and what angle up or down the plane was pointed.

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

Wire services