So there was a preliminary report which was released few days ago , Wednesday precisely..
The report said that there was no abnormalities before the China easter airlines plane crash which killed more than one hundred and thirty two people who were on board , the report was confirmed by the Chinese Civil Aviation Administration.
The Chinese civil aviation administration said that
"There was no abnormality in the radio communication and control command between the crew and the air traffic control department before deviating from the cruise altitude," the report said, before the Boeing 737-800 suddenly nosedived into the ground from 30,000 feet in the air
The Chinese aviation officials have made it known that they did not find any cause for the crash and that the crash is like a mystery to those who are investigating the matter and that they will continue to have an in-depth investigation with the support of the U.S. National Transportation Safety Board, the support of the U.S. Federal Aviation Administration and also the support of many other international groups...
The report have also confirmed that that cabin crew and all the other maintenance personnel really met all the requirements and also the plane was confirmed to be certified airworthy and also it was up to date on inspections...
Sources
https://www.nytimes.com/2022/04/20/business/china-eastern-crash-report.html
https://www.chinadaily.com.cn/a/202204/20/WS625ff455a310fd2b29e5829e.html