Jakarta. The black box containing flight data recorder (FDR) of a Sriwijaya Air plane which crashed four days ago was recovered on Tuesday by elite members of the Indonesian Navy.

Indonesian authorities are still working to locate a second black box that contains the cockpit voice recorder of the Boeing 737-500 plane, which carried 62 people during the ill-fated flight en route from Soekarno-Hatta International Airport in Banten to the West Kalimantan capital of Pontianak.

“Let’s pray that the process to read and retrieve data from the FDR -- which will take two to five days -- will go smoothly so we can confirm the cause of this tragedy,” National Transportation Safety Committee (KNKT) Chairman Soerjanto Tjahjono said in a statement.

“Uncovering the real cause of an accident will help us prevent a recurrence in the future, and that’s one of the main reasons of the ongoing investigation by the KNKT,” he added.

The air traffic control lost contact with the plane four minutes after takeoff on Saturday afternoon.

Soerjanto dismissed theory that the plane exploded mid-air, saying a broken fan blade still attached on its turbine disc has been found. In addition, the plane’s system continued to transmit data as it fell from an altitude of nearly 11,000 feet to as low as 250 feet.

“The damaged fan blade indicates that the engine was still functioning during the impact,” he said.