China's domestically developed single-aisle passenger jet C919 netted 40 new orders from Tibet Airlines at the opening day of the Singapore Airshow on Tuesday, while its debut at an overseas air show signals the model's official entry into the global civil aircraft market, said an industry expert.

Tibet Airlines, a regional carrier based at Gonggar Airport in Lhasa, Xizang autonomous region, signed a deal with Commercial Aircraft Corp of China for 40 C919 aircraft in the plateau variant. The variant meets transportation requirements in high-altitude areas by shortening the fuselage and featuring high-altitude modifications.

"The C919 aircraft participated in an overseas air show for the first time, promoting its global sales. We hope that the model will gain new orders from overseas carriers," said Lin Zhijie, a civil aviation industry analyst.

So far, the C919, comparable with the narrow-body Airbus A320 and the Boeing B737 series, has netted more than 1,100 orders from home and abroad. Two C919 and three ARJ21 regional aircraft made their debut at the Singapore Airshow.

As the global air travel market continues to recover from the COVID-19 pandemic, the C919 is expected to meet growing travel demand and break the market duopoly of Boeing and Airbus.

Tibet Airlines also signed an agreement with COMAC, the aircraft's manufacturer, for an order of 10 ARJ21 jetliners in the plateau variant.

The ARJ21 is China's first home-developed regional passenger jet, and the plateau variant has good crosswind resistance at high-altitude airports.

Currently, more than 110 ARJ21 aircraft are in commercial operation, with most operating at regional airports.

Meanwhile, Henan Civil Aviation Development and Investment Group signed an order with COMAC for six ARJ21 aircraft.

Airports located at an altitude above 1,500 meters and below 2,438 meters are considered high-altitude, and those at 2,438 meters and above are ultra-high-altitude airports. Such airports face significant difficulties due to the high altitude and sparse oxygen.

High-altitude airports are mainly in China, Nepal, Peru, Bolivia and Ecuador. Among the top 10 airports with the highest altitudes worldwide, China has eight, according to industry reports.

The C919's high-altitude variant has 140 to 160 seats, and its takeoff and landing performance meets the requirements of all ultra-high-altitude airports in China. The regular C919 passenger jet has 158 to 192 seats and a flying range of 4,075 to 5,555 kilometers, COMAC said.

"China boasts the world's biggest demand for high-altitude planes. The C919's plateau variant has a smaller passenger capacity, shorter fuselage and lighter weight. Corresponding modifications have been made to the engine and the oxygen system," Lin said. "The plateau variant is of great significance for meeting the travel demand of passengers in high-altitude regions of China," he added.

The Civil Aviation Administration of China has been implementing an initiative to better integrate regional connectivity with the trunk air travel market during the 14th Five-Year Plan (2021-25) period.

"China should further promote the development of the regional aviation market and launch more regional routes, and build a group of specialized and scaled regional carriers," said Li Guijin, a professor at the Beijing-based Civil Aviation Management Institute of China.

The C919 aircraft made its first commercial flight in May 2023. So far, four C919 jets have been put into commercial operations by Shanghai-based China Eastern Airlines and they have handled more than 110,000 passenger trips.

All four C919 planes were put into operation during the Spring Festival travel rush, which started on Jan 26 and will conclude on Mar 5.

The planes operate on regular round-trip routes connecting Shanghai Hongqiao and Beijing Daxing international airports, as well as Shanghai Hongqiao and Chengdu Tianfu International Airports in Chengdu, Southwest China's Sichuan province.