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An stewardess shows safety instruction on the flight EU2796, May 2, 2018. China's home-developed ARJ21 regional jetliner on Wednesday began to fly on new routes in northeast China's Heilongjiang Province, said its developer. The opening of new air routes with ARJ21 represent the model's commercial flight operations in the country's most northern and extreme cold region, said the Shanghai-based Commercial Aircraft Corp. of China (COMAC). (Xinhua/Ding Ting)

HARBIN, May 2 (Xinhua) -- China's home-developed ARJ21 regional jetliner on Wednesday began to fly on new routes in northeast China's Heilongjiang Province, according to its developer.

The opening of new air routes using the ARJ21 represents the model's commercial flight operations in the country's most northern and extreme cold region, said the Shanghai-based Commercial Aircraft Corp. of China (COMAC).

The new air routes include a 3,200-kilometer-long route between Harbin and Chengdu, capital of southwest China's Sichuan Province.

The ARJ21 will also be used in a further four new direct air routes in Heilongjiang: Harbin-Heihe, Harbin-Wudalianchi, Harbin-Fuyuan and Fuyuan-Jiamusi.

The ARJ21 is China's self-developed regional jet with 78 to 90 seats and a range of up to 3,700 km. It acquired certification in December 2014 and made its maiden flight in June 2016.

Mass production started in September 2017.

"Flying in cold regions challenges the aircraft's multiple key systems such as the engines, electrical power supply, environmental control and hydraulic pressure," said Chen Yong, chief designer of the ARJ21.

"The ARJ21 has already passed verification tests in the extreme cold weather," Chen said.

In December last year, the ARJ21 conducted more than 60 adaptive flights in seven airports in northern China's Heilongjiang and Jilin provinces to test its adaptation to extreme cold regions over 19 flight days.

Moreover, the ARJ21 also tested capacities in operating and flight support in airports in cold and mountainous regions.

To ensure the safety operation of the ARJ21 on its new air routes, Chengdu Airlines had dispatched one plane to conduct test flights in Heilongjiang for one month.

"It performed well even in the lowest temperature of minus 30 Celsius degrees," according to Chen.

Chengdu Airlines is the "launch customer" for the ARJ21 fleet. With the opening of new air routes, Chengdu Airlines has started the operation model of "trunk line plus regional line" with the country's home-developed civil passenger airplane model.

The new operating model of the ARJ21 represents a new phase in the commercial operation as well as the marketization and industrialization of China's jetliners, according to COMAC.

COMAC is also the developer of China's home-developed C919 passenger aircraft, which conducted its successful maiden flight on May 5 last year.

Chengdu Airlines will use the ARJ21 to build a regional aviation network connecting hub airports and regional airports in China.