SHANGHAI, Oct. 29 -- A regional airliner built by Commercial Aircraft Corporation of China, Ltd. (COMAC) started domestic test flights on Wednesday, a key step for its expected commercial debut at the end of this year.

A twin-engine ARJ21-700 completed a round trip at 10 a.m. between airports in Chengdu, capital of southwest China's Sichuan Province, and Guiyang, capital of neighboring Guizhou Province.

Take-off and landing were smooth and stable, according to a Xinhua reporter aboard the plane. It has eight seats for first-class passengers and 70 seats for economy class.

The jet, China's first homegrown commercial regional aircraft, completed a 30,000-km flight test around the world in April.

The jet will complete 300 hours of test flights in 10 domestic airports in the next month to simulate long-distance, medium-distance and short-distance routes, said Zhao Peng, the chief test pilot.

The test flights will test operations in rainy and dark conditions as well as system functions for air conditioning, auto pilot, communications, power, navigation and undercarriage, he said.

The jet, which has a maximum flight range of 3,700 kilometers and maximum altitude of 11,900 meters, is expected to be delivered to Chengdu Airlines by the end of this year after obtaining an operation certificate from authorities.

"We do not expect the ARJ21-700 to be a star," said a staff member who participated in the test flight on condition of anonymity. "We would rather the jet be a plain passenger airplane that is safe, stable and reliable to be the best company for passengers."

COMAC has so far received orders for more than 250 ARJ21-700 jets from customers at home and abroad. But it is facing fierce competition from its foreign rivals, including Brazil-based Embraer's ERJ190 and Canada-based Bombardier's C Series.

So far, four ARJ21-700 jets have completed more than 4,500 hours of tests since a maiden flight in November 2008. COMAC is also working toward gaining certification from the U.S. Federal Aviation Administration (FAA) in order to make the ARJ21 the first Chinese commercial aircraft to receive U.S. approval.

This could help sell the aircraft overseas. The FAA has agreed to launch a shadow certification, which involves ensuring the certification process by the Civil Aviation Administration of China is in line with FAA standards.