Last June, the CAAC called a workshop with domestic carriers including Kunpeng Airlines (the predecessor of Henan Airlines) to discuss problems concerning the imported ERJ-190 jets.

Breaks of the turbine plates and "erroneous information" displayed in the flight control system were among the most prominent problems, the workshop notes showed.

But a spokeswoman for Embraer's branch in China said on Wednesday that there are no such problems and that she has not heard of them before.

She refused to elaborate, but reiterated that the Brazilian company has sent a technical team to help with the investigation on the crash.

The CAAC has not issued any notice asking airlines to carry out overall checks on the same plane model "because the reason for the crash is still yet to be revealed", said an official who spoke on condition of anonymity.

Such a notice would only be issued if the investigation found problems with the plane, he said.

While the cause of the crash is still unknown, industry observers pointed to "statistical coincidences" in the past two air crashes.

"It seems that accidents often follow airline reshuffles," said Li Xiaojin, a professor with the Civil Aviation University of China.

For example, the last accident in 2004, in which a China Eastern Airlines plane crashed shortly after take-off in Baotou city of the Inner Mongolia autonomous region, occurred after a major reshuffle of China's air transport industry in 2003, he said.

As for the crash on Tuesday, Shenzhen Airlines, the parent company of Henan Airlines, is also undergoing a reshuffle with Air China, which gained control of Shenzhen Airlines in March this year, he said.

"Airlines sometimes have different safety management systems, in which some rules might even contradict each other," Li said.

"It takes time for a reshuffle to complete and plug holes in the systems."

At least one airline has also noted that the Yichun airport where the crash occurred is not safe for nighttime landings.

The airport, which opened one year ago, is located in a forested valley, which can complicate landings at night, according to a document by the Heilongjiang branch of China Southern Airlines on Aug 27, 2009.

The document banned night landings at the Yichun airport from Sept 1.

The airport has been closed following the accident.