SHANGHAI — The ARJ21, China's first turbo-fan regional passenger jetliner, has gained further progress with two more airplanes beginning test flight this year, according to its developer on Feb 24.

The test flight showed that the civil airplane model is on track of smooth development and delivery with more airplanes in the fields of intensive tests and commercial operation, said the developer, the Commercial Aircraft Corporation of China (COMAC).

Of the two planes that underwent test flight on Feb 22, the No 103 aircraft focused on the flight test missions of the optimal design of the ARJ21. It is of crucial importance for the COMAC to verify the airplane's performance during its continuous improvement.

The test flight also marked the maiden flight of the No 131 ARJ aircraft, which will be delivered to Chengdu Airlines after the test flight stage.

As a pioneer of Chinese commercial airplanes, the ARJ21 aircraft was put into commercial service in June 2016. To date, the COMAC has delivered a total of 23 ARJ21 airplanes.

In the nationwide joint anti-epidemic fight, this Chinese civil airplane model is playing its role in emergency transport missions carrying personnel and supplies to support the virus-hit regions.

On Feb 21, Chengdu Airlines sent a fleet of five airplanes, including four ARJ21 airplanes, to carry 231 medical staff from cities around Southwest China's Sichuan province to Central China's Hubei province, the epicenter of the ongoing novel coronavirus outbreak, according to the airline.