STORY: China says the black boxes from a Boeing jet that crashed there last month are severely damaged.
That means it will take time to recover and analyse the data they hold.
The 737-800, operated by China Eastern Airlines, went down in the mountains of Guangxi on March 21.
All 132 people on board died.
The black boxes were subsequently recovered, and sent to the U.S. for analysis.
In a statement on its preliminary report, the Civil Aviation Administration of China did not make public any information recovered from the flight recorders.
It said the crew were fully qualified, the jet was well maintained, the weather was fine and there were no dangerous goods on board.
That leaves the cause of the crash as a mystery.
And one aviation expert says it could take a year to glean clues from the black boxes.
China Eastern has begun flying 737-800s again following the crash.
It’s a different model from the 737 MAX, which remains grounded in China following two deadly crashes in other countries.