JAKARTA, Indonesia (CNN) — Searchers have retrieved the flight data recorder of AirAsia Flight QZ8501 from the Java Sea, officials said Monday, a major breakthrough in the effort to figure out why the plane crashed last month.
The device was found under the wreckage of one of the plane’s wings, said Bambang Soelistyo, the head of Indonesia’s search and rescue agency.
But the other key source of information about the plane, the cockpit voice recorder, hasn’t been found yet, officials said.
The two devices, known popularly as black boxes, are seen as crucial to unraveling the mystery of what brought down Flight QZ8501 as it flew toward Singapore from the Indonesian city of Surabaya with 162 people on board.
Finding the data recorder is “a huge step in the right direction for investigators,” said CNN aviation correspondent Rene Marsh. “It gives them so much information that they didn’t have before.”
Coupled with the debris that’s already been collected, the data recorder will enable investigators to “begin to paint the picture of exactly what happened when things went terribly wrong for this aircraft,” Marsh said.
Device’s location ‘is a clue’
The data recorder is expected to provide a vast range of information about what the plane was doing, including its air speed, engine performance and the cabin pressure.
The discovery of the device under the wreckage of a wing is significant, according to Mary Schiavo, a former inspector general of the U.S. Department of Transportation.
“That itself is a clue, because I think that pretty much indicates that the plane broke apart when it hit the water,” she said, adding that if the aircraft had broken up at a high altitude, investigators wouldn’t “have found the wreckage that close together.”
The cockpit voice recorder, which searchers are still hunting for in the murky waters of the Java Sea, captures all sounds on the flight deck, notably conversations between the pilots.
Data expected to be intact
The condition of the flight data recorder wasn’t immediately clear, but Marsh said it was likely to have come through the crash with its information intact.
“They are built to withstand the most severe aircraft accidents,” Marsh said. “We’re talking about high temperatures, we’re talking about pressure from being at the depths of the ocean.”
The tail section of the aircraft, which houses the black boxes, was lifted from the Java Sea on Saturday. But searchers didn’t find the flight recorders within.
Flight QZ8501 went down on December 28. It was operated by AirAsia’s Indonesian affiliate.
CNN’s David Molko reported from Jakarta, and Jethro Mullen reported and wrote from Hong Kong. CNN’s Kocha Olarn contributed to this report.