On August 21st, it was learned from Commercial Aircraft Corporation of China (COMAC) that an ARJ21 aircraft from COMAC took off from Shuangliu International Airport in Chengdu, Sichuan on the same day. After a 50 minute flight, it successfully arrived at the Red Plains Airport in Aba, Sichuan at an altitude of over 3500 meters, marking the official start of the more than month long demonstration flight of the domestically produced regional aircraft ARJ21 around the Qinghai Tibet Plateau. COMAC said that during the demonstration flight of "Around the Qinghai Tibet Plateau", ARJ21 will fly to several high plateau airports in Xizang, Sichuan, Qinghai and Gansu, taking Chengdu, Xining and Lhasa in Xizang as the operating bases, to fully verify the adaptability of ARJ21 to high plateau airports and routes, the adaptability of airport ground service equipment and the applicability of special flight procedures, so as to better and more comprehensively meet the operational requirements in high altitude areas. According to the regulations of the Civil Aviation Administration of China, airports with an altitude of 2438 meters or above are considered high-altitude airports. At present, there are 25 high-altitude airports in China, accounting for more than 50% of the total number of high-altitude airports (with runway lengths of over 2000 meters) in the world. The air in high-altitude areas is thin, the terrain is complex, and the weather is variable, which requires extremely high requirements for aircraft performance, crew qualifications, and operational support capabilities. In early July 2024, the ARJ21 aircraft operated by Chengdu Airlines opened its first high-altitude route - a regular flight from Kashgar, Xinjiang to Tashkurgan. The flight has been in good condition for more than a month, bringing convenience to local people's transportation. COMAC stated that in recent years, with the development of China's economy and society, the demand for civil aviation transportation in high-altitude areas has gradually increased, and the demand for aircraft that can adapt to high-altitude airports and routes is also increasing. At the beginning of its design, the domestically produced ARJ21 regional airliner took into account the operational conditions in western China, with high-altitude performance as an important indicator, and conducted demonstration flights in Yunnan, Xinjiang and other places. This demonstration flight around the Qinghai Tibet Plateau will further verify the high-altitude operational performance of the ARJ21 aircraft, laying the foundation for domestic commercial aircraft to open more high-altitude routes and accelerate the implementation of the "Border Express". It is reported that the ARJ21 aircraft is China's first domestically developed short to medium range turbofan regional airliner with independent intellectual property rights in accordance with international civil aviation regulations. It has a seating capacity of 78-97 seats and a range of 2225-3700 kilometers. The ARJ21 aircraft obtained the model certificate from the Civil Aviation Administration of China in December 2014 and the production license in July 2017. Since its official launch in June 2016, the ARJ21 aircraft market has been operating and selling well. (New Society)