“If the data storage chip is damaged, it would generally be sent to the recorder manufacturer for repair.”

The Boeing 737-800 crashed on Monday with 132 people on board in China’s worst aviation disaster in more than a decade.

The two recorders on board were produced by US-based company Honeywell.

The second black box – a flight data recorder – captures information including aircraft conditions, plane performance and pilot input.

It is designed to survive high-impact crashes but the search for the device is being complicated by extreme humidity and stringent Covid-19 prevention measures.

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Human remains found at China Eastern plane crash site as temporary road built to help investigation

Human remains found at China Eastern plane crash site as temporary road built to help investigation

According to the Convention on International Civil Aviation, the country conducting the investigation is expected to produce a preliminary report within 30 days of the crash and decides whether to make it public or keep it confidential.

Orange debris believed to be from one of two black boxes on the aircraft was recovered on Friday morning in the terraced fields of Teng county in the Guangxi Zhuang autonomous region.

No survivors have been found in the search, which involves more than 2,000 people from the armed police force, fire service and militia, according to local authorities.

Authorities said rescue teams had found more human remains and wreckage, including part of the engine and landing gear.

Lao Gaojin, deputy mayor and public security bureau director of Wuzhou, a city near the crash site, said the team had extracted 18 fingerprint samples and found 101 personal items by Friday afternoon, adding that experts had been working overtime to identify the victims and carry out DNA tests.

Wreckage previously recovered includes parts of an engine blade, turbine and wings of the Boeing 737-800.

Zhu Tao, the aviation safety director at the CAAC, said emergency response teams had started collecting DNA samples from direct relatives of the passengers, adding that 375 family members had visited the crash site to pay their respects.

The possible find was first reported on Friday by CAAC News, a newspaper run by the Civil Aviation Administration of China, on its WeChat and Weibo accounts and shared by other state media outlets. It later apologised, saying the report was inaccurate.

Searchers are looking for the flight data recorder to shed light on why the aircraft nosedived before impact.

The device stores information such as flight path, speed, altitude and engine power and can reveal whether human error or instrument problems contributed to the crash.

The aircrew sent no emergency code and communication was normal before the flight lost contact, according to Liu Xiaodong, the airline’s brand management director.

Heat and Covid-19 prevention measures are adding to the difficulties of searching the hilly site.

State broadcaster CCTV aired footage of emergency workers in masks, protective suits and boots scouring the muddy hills on Friday after torrential rain and a landslide a day earlier. By noon, the temperature at the site was already around 30 degrees Celsius (86 degrees Fahrenheit).

“It’s very muggy today,” a CCTV host reported from the scene. “Given the rain and high temperature, Covid-19 prevention is very important. So everyone working on the scene wears protective suits.”

Citing an unnamed expert, the host said: “It’s likely the second black box is somewhere near the place the orange debris was recovered.”