Two of China's domestically developed C919 large passenger jets have completed a month-long round of demonstration flights in northwest China's Xinjiang Uygur Autonomous Region, with homegrown jetliners showing exceptional performance.

Xinjiang was chosen as the testing site for its complex terrain, diverse climate, volatile weather and ideal airport conditions.

A series of demonstration flights were carried out by their developer, the Commercial Aircraft Corporation of China (COMAC), since August 24.

Using the Urumqi airport as a base, the C919 planes flew to nine airports, covering 41 flight segments with a total flight time of over 64 hours.

The flights testified to the large passenger aircraft's adaptability to the flight routes and airport conditions in Xinjiang, according to the COMAC.

The first C919 aircraft made its inaugural commercial flight between Shanghai and Beijing on May 28, and two such aircraft have entered regular service between east China's Shanghai Municipality and Chengdu City in southwest China's Sichuan Province.

Also participating in the demonstration flight was an ARJ21 aircraft, China's first independently developed short-medium-range turbofan regional aircraft.

The ARJ21 aircraft has undergone 184 flight segments, with a total flight time of 276 hours.

The demonstration flights will pave the way for the large-scale operation of the ARJ21 aircraft in Xinjiang, said Tong Yu, deputy general manager of COMAC Shanghai Aircraft Customer Service.

In early June this year, the first ARJ21 aircraft started commercial operations in Xinjiang, and it is expected to reach five by the end of this year, meeting passengers' needs for short-distance travel, according to COMAC.