Have you bought a ticket for the C919 during the National Day holiday?

Welcome National Day

The "artificial sun" broke the record again, the domestically-made large passenger aircraft C919 achieved commercial operation, Xinjiang's saline-alkali land had a bumper harvest of seafood, the medical heavy ion accelerator was put into clinical application, the first domestically-made large cruise ship "Aida Magic City" successfully completed its sea trial, and the world's deepest underground laboratory was waiting for a "visit" from dark matter... In 2023, my country's science and technology continued to make new breakthroughs, bringing new possibilities and opportunities to human life and development.

On the occasion of the 74th anniversary of the founding of the People's Republic of China, Digital Beijing Science Center has brought you a special column "Great Power Science and Technology Style", allowing us to review the scientific and technological achievements made this year under the leadership of the Party.

Review expert: Zhao Liangyu, Associate Professor of Flight Control Department, School of Aeronautics and Astronautics, Beijing Institute of Technology

Have you been flooded with news about domestically produced large aircraft this year?

Source: Beijing News

On May 28 this year, the first commercial flight MU9191 operated by China's domestically-produced large aircraft C919 with completely independent intellectual property rights took off smoothly from Shanghai Hongqiao International Airport and arrived at Beijing Capital International Airport. It passed through the "water gate" symbolizing the highest etiquette of civil aviation and successfully completed the world's first commercial passenger flight of this aircraft. On that day, more than 130 passengers took the lead in experiencing the C919's aerial journey. The next day, China Eastern Airlines' first C919 large passenger aircraft started regular commercial operation on the Shanghai Hongqiao-Chengdu Tianfu route.

Source | Beijing University of Aeronautics and Astronautics

On August 4, China Eastern Airlines launched its second C919. Today, the domestically-made C919 has been in commercial operation for more than 100 days, with orders exceeding 1,000. During this National Day holiday, passengers can personally experience riding on a C919 and feel the charm of the domestically-made large aircraft.

The full name of C919 is "COMAC919", which is the abbreviation of the English name of the main manufacturer of C919, Commercial Aircraft Corporation of China. "C" is the first letter of "COMAC" and the first letter of China's English name "CHINA", which reflects that large passenger aircraft are the will of the country and the expectation of the people. In the number, the first 9 means "eternity", and 19 means that the maximum passenger capacity of C919 large passenger aircraft is 192 people.

Under the blue sky, the C919 soars like an eagle, bringing China's aviation industry to a new peak. It not only represents advanced technology and manufacturing level, but also symbolizes China's firm determination for independent innovation.

Source | China Eastern Airlines

China's giant wings, dream-building journey

In 2006, the State Council issued the Outline of the National Medium- and Long-Term Science and Technology Development Plan (2006-2020), which identified the major project of large aircraft as one of the 16 major science and technology projects, and pointed out the direction for China's aviation industry. At that time, domestic large passenger aircraft had long relied on imports, and foreign suppliers had formed a monopoly. In order to enrich the civil aviation industry economy and have the ability to independently develop and produce its own large passenger aircraft, the C919 project came into being.

During the development of C919, my country faced a series of technical difficulties. However, "from nothing comes something, from something comes one", and the technological breakthroughs are the crystallization of the sweat and wisdom of engineers who have silently contributed. They overcame difficulties in many fields, and finally the C919 large aircraft took to the runway for its first flight on May 5, 2017.

Source | CCTV News

How to determine the design life of an aircraft - aircraft life determination technology is a difficult problem encountered during the research and development process. If it is still designed according to Boeing's DFR method like China's previous ARJ series, due to issues involving patents and technical standards, China may need to negotiate with Boeing on issues such as technology licensing and patent royalties. C919 may have technical and economic disputes in terms of airworthiness certification, and its autonomy will also be restricted. To this end, the C919 research team has conducted detailed research and comprehensive summaries of China's decades of military aircraft airworthiness, safety, and reliability technologies, benchmarked against international standards, and proposed a C919 life determination plan with complete independent intellectual property rights.

The overcoming of countless similar technical difficulties not only demonstrates the indomitable scientific research spirit of Chinese engineers and researchers, but also injects confidence into the future development of China's aviation industry.

The light of science and technology shines in the blue sky

The success of China's domestic large aircraft is inseparable from the deep cultivation of multiple scientific and technological fields in my country. Since 2006, various relevant scientific research teams have invested tremendous efforts, and the improvement of scientific and technological levels is a solid support for the C919 to soar into the blue sky.

C919 introduces advanced structural design. The structural design and materials of an aircraft are like its skeleton and muscles, which determine the strength and weight of the aircraft. The supercritical wing is one of the characteristics of China's large aircraft C919. "Compared with the Boeing B787's 'scimitar' wing design, the C919's wing is more restrained."

This "restrained" wing was carefully selected by the design team from more than 2,000 wing design proposals. It is also the first fully independently designed supercritical wing in China. It can adapt to high-speed cruising flight while maintaining high aerodynamic efficiency. On this basis, the technical team also innovatively adopted a partial fusion design between the critical wing and the engine, fuselage and suspension, reducing the drag coefficient by 5%. It is this 5% that reduces fuel consumption and costs to a certain extent.

Source | China Eastern Airlines

C919 is the first to use advanced materials on a large scale , significantly reducing the weight of the aircraft structure, saving fuel consumption and improving economy. The tail section of the aircraft, including the rear fuselage, horizontal tail and vertical tail, all use composite materials, mainly carbon fiber reinforced resin-based composite materials, which have many advantages such as light weight, corrosion resistance, fatigue resistance, and integral molding. The third-generation aluminum-lithium alloy was used on the fuselage on a large scale for the first time, and the third-generation aluminum-lithium alloy was fully domestically produced. Aluminum-lithium alloy has the characteristics of low density, high strength and good damage tolerance. Data shows that using it to replace conventional aluminum alloy materials can reduce the density of aircraft components by 3%, reduce weight by 10%-15%, and increase stiffness by 15%-20%.

C919 also introduces advanced cabin integrated design technology . The cabin height of C919 reaches 2.25 meters, and the arc-shaped roof design brings passengers a stronger sense of space and a more spacious riding environment. Compared with the Airbus A320 and Boeing 737 of the same level, it is more spacious, and the passenger experience and cabin comfort are better. The size of the middle seat is 18.5 inches, which is 0.5 inches more than the seats on both sides, providing more comfort for passengers in the middle seat. The design of the adjustable pillow that can be pulled up and down can reduce neck fatigue for passengers of different heights and body shapes. Through humanized design, the cabin comfort is improved and a more pleasant riding experience is provided.

Source | News Photo

The C919 is the product of China's technological breakthroughs in many fields. These technological advances have laid a solid foundation for the steady development of China's science and technology.

Wings of the future, innovation never stops

The birth of China's domestic large aircraft represents a huge leap forward in China's independent intellectual property research and development, and is also a great victory in the transition from "Made in China" to "Smart Manufacturing in China". The success of C919 is the result of national policies and technological innovation. The rise of China's domestic large aircraft also demonstrates China's technological strength and ambition in the aviation field, injecting new vitality into the world's aviation industry.

In the future, China will continue to invest in and develop large aircraft technology, and enhance independent innovation capabilities in various important fields, accelerate technology transformation, and promote the development of independent intellectual property rights. The road of scientific and technological innovation will never stop, and will write a more glorious chapter for the country's development and prosperity.