"China can produce helicopters with a take-off weight from 1 ton to 13 tons, but only the United States and Russia can produce choppers with lift-off weight of more than 20 tons," said Xia Qunlin, deputy general manager of Avicopter, a joint venture between Aviation Industry Corp of China (AVIC) and the Tianjin municipal government.

"If approved by the government, the 33-ton heavy helicopter is expected to fill a gap in China... and play important roles in rescue missions and fighting forest fires," he said.

Avicopter Co Limited and Russian Helicopters are now discussing its feasibility, which includes sizing up the model's market and determining both sides' investment shares and division of work, he said.

If approved by the government, this heavy-lift helicopter will be developed and put into service in five to seven years, he said, adding it will be produced at Avicopter's Tianjin production base.

The country realized its need for heavy-lift helicopters in 2008, when a devastating earthquake in Sichuan province killed more than 69,000 people.

A rented Russian Mi-26 heavy chopper demonstrated its importance in rescue work by lifting a 13.2-ton bulldozer and other large pieces of machinery into areas that became isolated after roads linking them to the outside were destroyed.

Premier Wen Jiabao later urged the country's aviation industry to develop such heavy-lift helicopters.

In October 2008, Wen and Russian Prime Minister Vladimir Putin witnessed the signing of a memorandum of understanding between AVIC and Russian Helicopters on jointly developing heavy-lift helicopters.

However, the jointly developed heavy chopper will be "more reliable and more economic to use" and "suit China's demands better", he said.

China is believed to be a big potential market for helicopters.

By the end of 2010, there were only 206 registered civilian-use helicopters across the country, which is less than 1 percent of the total civilian helicopters in the world. Avicopter forecast that with the relaxing of low-altitude airspace, the demand for helicopters will grow quickly, and the mainland will need 200 civilian helicopters between 2011 and 2015.

As the only State-owned chopper producer, Avicopter accounts for about 60 percent of the domestic market, according to Xia.

The company currently has four helicopter production bases including Harbin, in Heilongjiang province, Jingdezhen, in Jiangxi and Baoding, in Hebei.

Yang Chunhai, who is in charge of production and technologies at the Tianjin base, said the Tianjin base will become where all civilian helicopters are assembled and go through test flights.

Built two years ago, the Tianjin base will produce 10 helicopters through two production lines this year, he said.

According to Xia, the Tianjin base's capability is expected to double next year, and it is able to assemble 150 civil-use helicopters by 2020.