On the 5th, C919 made its first flight smoothly. Around this domestic big plane, netizens had many problems. Why did we build a big plane? Because jet trunk passenger aircraft is a very complicated industrial product, only the United States, Russia and Europe have independent research and development capabilities in the world so far, which shows the great difficulty. So, there are already so many big planes in the market. Why don’t China buy them directly and spend 10 years developing them by itself? This is also one of the issues that netizens are very concerned about. They continue to follow CCTV reporters to China shangfei to find the answer.
Shanghai Pudong China Commercial Aircraft Test Flight Center
CCTV reporter Zhao Zhongliang: large dry line passenger plane is known as a flower in the modern industrial field, because it covers a wide range of subjects and its technical difficulty is also very high, therefore, only a few countries in the world can develop it. When we collected questions on the Internet, many netizens also asked why our country developed such a large passenger plane? The cost of its investment is also very high, and it takes a long time and a lot of manpower. To answer this question, let’s start with a detail on C919. The research and development of C919 has enabled many fields in our country to complete changes from scratch and from weak to strong. For example, the landing gear in front of me is the main landing gear of C919, which bears very strong force and can withstand the impact force of 75 tons of fully loaded C919 when landing, and its life span is the same as C919 itself, which is life-long. The steel used in this landing gear was driven by the research and development of C919, achieving a breakthrough from zero to some.
Go to Baosteel, Shanghai Baoshan Baosteel Special Steel branch, China’s largest iron and steel enterprise, and one of the earliest special steel production bases in China.
CCTV reporter Zhao Zhongliang: The two steel column in front of me are steel used for C919 landing gear, 300m steel. 95% of the aircraft landing gear in the world uses this material, which is praised as one of the key technologies in the field of aviation materials and has been monopolized by foreign countries for a long time. It took five years for the engineers of Shanghai Baosteel special steel to produce this kind of special steel with strict standards when the production cost was reduced by 50%, the price-performance ratio has been ranked among the top in the world.
Now, 300m steel and the production line it uses have been certified as the world’s highest standard for aviation material suppliers. Every 300m steel will be placed in the pool next to me, and the 360-degree inspection without dead angle will be completed by ultrasonic wave. The steel structure, density and even more than 20 other elements contained in it should be completely uniform. It should be said that under the traction of the C919 large passenger plane, made in China has also reached a completely new level of height.
In the department assembly workshop, work and assembly. Shanghai Pudong C919 assembly manufacturing workshop.
Look at the composite material of C919
CCTV reporter Zhao Zhongliang: in addition to the realization of special materials, C919 has actually achieved a brand-new pull for the entire aviation industry in China. We are now in the C919 assembly workshop, here, the second aircraft of C919 is in the process of assembly. In the process of preparing for the first flight of C919, it will also complete the assembly soon and finally join the test flight team. At this stage, we can see more clearly the real materials used by C919.
In order to obtain more excellent performance, most of the body of C919 uses the most advanced aviation aluminum alloy so far-the third generation lithium aluminum alloy. This special aviation aluminum alloy is not only lighter in material, but also stronger, it should be said that it is a material with higher cost performance. In addition, C919 also uses a large number of composite materials. As you can see, starting from the rear hatch referred to by my hand, all the materials used in the future are composite materials, so the proportion of materials used in C919 is also the largest in China’s aviation field at present, reaching about 12%, and such a large area, it is also a brand-new challenge for China’s aviation field. More importantly, the use of composite materials in such a large area has also led to greater development of this industry.
Zhenjiang, Jiangsu aerospace Seahawk special material
CCTV reporter Zhao Zhongliang: I am now in the production workshop of C919 composite materials. This is a million-level clean factory. Now we can see that the staff took off the cut composite materials one by one. Through such small pieces, the materials used on our C919 can be finally formed. Just like a piece in my hand, it is a bit like our common mobile phone film. There is a layer outside and a layer below, and the middle is a cloth made of carbon fiber. The transverse strength of this cloth is very good, stronger than steel. And I have more than 3,000 pieces in a small piece. This very special material is very thin, but how did it become a hard aviation material?
The composite material goes to the next step here. We see that the staff stick it to the mold, and then stick it one by one, stick it to a specific thickness, and calibrate it with laser, finally, it was put into the high temperature and high pressure furnace, and the final output was such a component in my hand. It is such a main bearing structure located at the tail of C919. As you can see, the strength is very good. At the same time, this structure is very light, about 50% lighter than the same aviation aluminum alloy. Now the aviation composite materials used on our C919 have reached the same level as the most advanced composite materials such as Boeing 787 and Airbus 350.
Through the traction of C919, we can not only produce such small parts, but also produce such large parts independently. And what we can expect is that one day, the main bearing structure of the car we drive can use such carbon fiber composite materials.
On the 5th day of 2996, C919 made its first flight smoothly. Around this domestic big plane, netizens had many problems. Why did we build a big plane? Because jet trunk passenger aircraft is a very complicated industrial product, only the United States, Russia and Europe have independence all over the world so far.