Where are the black boxes?

Indonesian officals confrim that the tail of missing AirAsia plane has been found in the Java sea.

Crashed ... The AirAsia plane with 161 people on board lost contact with ground control on Sunday, December 28, while flying over the Java Sea. Pic: AP Photo/Joshua Paul Source: AP

THE tail of AirAsia Flight QZ8501 that crashed more than one week ago has been found in the Java Sea, the Indonesian search and rescue chief has confirmed.

The discovery on the seabed, 11 days after the flight disappeared, could mark a breakthrough in the search as the tail of a plane usually houses the "black box" flight data recorders, crucial to determining the cause of a crash.

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"We have successfully obtained part of the plane that has been our target. The tail portion has been confirmed found," National Search and Rescue chief Henry Bambang Soelistyo told reporters in Jakarta.

He said he was sure of the discovery after seeing photographs of the underwater wreckage, on which the company logo could be seen.

One released image appeared to show an upside down "A" painted on a piece of metal, while another grainy shot depicted some sort of mechanical parts.

The crucial part from the wreckage was discovered about nine kilometres from where the plane lost contact - after it was detected by an Indonesian survey ship.

Tail wreckage from missing AirAsia plane, found on Wednesday by Indonesia's search and rescue divers. Picture: AP Source: AP

Wreckage from the ill-fated AirAsia Flight 8501, as identified by BASARNAS. Picture: AP Source: AP

Underwater wreckage of missing AirAsia Flight 8501. Picture: AP Source: Supplied

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Following days of strong currents and murky water that hindered the operation, searchers finally managed to get some of the first photographs of the debris near the seabed.

"Today we successfully discovered the part of the plane that became the main aim since yesterday," Mr Soelistyo said.

Being analysed ... Chief of National Search And Rescue Agency (BASARNAS) F. Henry Bambang Soelistyo shows an underwater photo of a part of the wreckage. Picture: AP Source: AP

"I can ensure that this is part of the tail with the AirAsia mark on it."

The find is particularly significant because the all-important cockpit voice and flight data recorders, or black boxes, are located in the aircraft's tail. Small pieces of the plane, such as seats, have previously been spotted.

Ongoing search ... Indonesian Navy personnel with personal luggage and wreckage from the AirAsia QZ8501 plane crash site that were found in the Java Sea. Picture: Robertus Pudyanto/Getty Images Source: Getty Images

"I am led to believe the tail section has been found. If right part of tail section then the black box should be there," AirAsia boss Tony Fernandes wrote on Twitter.

"We need to find all parts soon so we can find all (our) guests to ease the pain of our families. That still is our priority."

Finding the black boxes will be key to the investigation. They provide essential information including the plane's vertical and horizontal speeds along with engine temperature and final conversations between the captain and co-pilot.

The ping-emitting beacons still have about 20 days before their batteries go dead, but high surf had prevented the deployment of ships that drag "ping" locators.

Sonar-equipped ships involved in the massive international hunt have also identified what they believe to be the fuselage of the plane.

Looking for answers ... a crew member of Japan Maritime Self-Defense Force ship JS Onami uses his binoculars during a search operation for the victims of AirAsia Flight 8501. Picture: AP Source: AP

Mr Soelistyo said the top priority remains recovering more bodies along with the black boxes. So far, 40 corpses have been found, including an additional one announced, but time is running out.

At two weeks, most corpses will sink, and there are already signs of serious decomposition, said Anton Castilani, head of the country's disaster identification victim unit.

To date, action has been taken against eight officials — "two from the transport ministry, four from state navigation operator AirNav, and two airport officials," transport ministry official Hadi Mustofa said.

More seats found ... members of the Indonesian Navy carry wreckage recovered from the Java Sea of AirAsia flight QZ8501 upon its arrival at Juanda military airport in Surabaya. Picture: AFP Source: AFP

"One of the transport ministry officials was fired and the other official was temporarily suspended.

"As for the other six officials, some have been temporarily suspended and some have been transferred."

AirAsia Indonesia has declined to comment on allegations it violated its permits. Singapore authorities say the Sunday flight schedule had been cleared at their end.

At work ... Indonesian navy ship 'KRI Sultan Hasanudin' is seen through the window of a Super Puma helicopter during a search operation for AirAsia flight QZ8501. Picture: AFP Source: AFP

Mustofa said the ministry was checking all domestic airlines for any other flight violations and would announce its findings later this week.

The Airbus A320-200, with 161 people on board, lost contact with ground control on Sunday, December 28, while flying over the Java Sea after taking off from a provincial city in Indonesia for Singapore.

Search and rescue operations have since been underway but have been dogged by bad weather.

Since the plane crashed, many theories about what may have caused the demise of flight QZ8501 have emerged.

But aviation experts have cautioned that only the black boxes can reveal the truth.