Exploring domestic large aircraft: from Yun -10 to C919, realize the blue sky dream step by step.

  On May 5, 2017, 101 aircraft of C919 large passenger plane successfully made their first flight. Photo courtesy of China Commercial Aircraft Corporation

  The cockpit of Yun -10 aircraft. Our reporter Zhang Pengyu photo

  The production line of ARJ21 in Dachang Base of COMAC General Assembly Manufacturing Center in China is very busy. Photo by Zhang Haifeng

  C919 first aircraft group. Photo courtesy of China Commercial Aircraft Corporation

  The ARJ21 aircraft conducted a cold test flight in Hailar, Inner Mongolia. Photo courtesy of China Commercial Aircraft Corporation

  On May 5, 2017, people with big plane dreams came to a small slope outside the fourth runway of Shanghai Pudong International Airport early, waiting for the exciting moment. On this day, it was the first flight day of C919, a large jet passenger plane independently developed by China, and the small earth slope outside the runway was affectionately called "Wangjiupo".

  With the roar of the engine, the first C919 large passenger plane, piloted by captain Cai Jun and co-pilot Wu Xin, took off from the fourth runway of Pudong International Airport at 14: 00, rushed into the sky, and landed successfully 79 minutes later. After nine years of scientific research, numerous tests and technical debugging, there is once again the shadow of domestic large aircraft in the blue sky, which indicates that China has entered the ranks of a few countries with the ability to develop large passenger aircraft.

  Now, more than two years have passed. What’s the progress of airworthiness certification of C919 passenger plane? When can Chinese get on a large domestic plane? Recently, the reporter came to China Commercial Aircraft Co., Ltd. for a field visit.

  Yun -10: Leaving an innovative gene is an attempt to commercialize domestic aircraft.

  Arriving at the Pudong base of China Comac Shanghai Aircraft Manufacturing Co., Ltd., I saw a large plane with a white fuselage and several blue and white stripes sleeping peacefully on the lawn of the industrial park, with a bright red flag on its tail. This unique large passenger plane in the world soared in the blue sky of China more than 30 years ago, and its name was Yun -10.

  Boarding the Yun -10 plane, the reporter was shocked by the industrial level at that time. The throttle lever, pedals, various instrument panels and indicator lights in the cockpit are reasonably arranged and fully functional. In addition to the seats for the main driver, the co-pilot and the pilot, there is also a seat for the mechanic. When the aircraft breaks down in flight, the mechanic can go down to the inside of the aircraft from the passage next to the seat for maintenance. When you come to the cockpit, the passenger seat is no different from the common big plane now, except that the distance between the front and back of the seat is larger, the ride experience is more comfortable, and there is an ashtray on the armrest.

  In August 1970, with the approval of Comrade Zhou Enlai, the state agreed that the report on trial production of transport aircraft in Shanghai should be centralized by the Ministry of Aviation Industry. The mission name is "Project 708" and the aircraft code is "Yun -10". According to statistics, at that time, more than 300 factories, research institutes and universities in 21 provinces, autonomous regions and municipalities participated in the development of Yun -10 aircraft.

  On September 26th, 1980, Yun -10 successfully made its first flight in Shanghai. Subsequently, Yun 10 flew all over the country, reaching 10 cities, including Beijing, Harbin, Urumqi, Guangzhou, Kunming, Chengdu, Hefei and Zhengzhou. The longest time for a single flight was 4 hours and 39 minutes, and it completed a scientific test flight that flew over 3,600 kilometers in 3 hours and 42 minutes. Its performance and use characteristics fully met the design requirements. Yun -10 also flew over the Himalayas to Tibet seven times, transporting more than 40 tons of urgently needed materials for Xizang Autonomous Region.

  Although the Yun -10 aircraft project was not officially put into commercial use for various reasons, the Yun-10 spirit of "independence, strong cooperation, selfless dedication and continuous innovation" has been passed down from generation to generation by large aircraft people.

  Next to the lawn where Yun -10 plane docked, there stands a sculpture engraved with the four characters "Never give up", which is a solemn promise from the heart of the big plane people and the earnest expectation of hundreds of millions of people for the early commercialization of domestic big planes.

  Time has entered the new century. In February 2000, the state decided to support the production of domestic civil aircraft and accelerate the development of regional air transport. In June, 2002, the State Development Planning Commission issued a document officially approving the establishment of the new regional aircraft project. The result is a new turbofan regional plane that has soared in the blue sky of China today — — Arj21 (advanced regional jet for 21st century) means advanced jet regional aircraft in the 21st century. ARJ21-700 is its basic model, and it is the first time that China has developed and produced regional aircraft in strict accordance with the internationally accepted regulations on aviation airworthiness management.

  ARJ21: Delivered the 21st aircraft, accumulating valuable experience for the civil aircraft industry.

  Not long ago, on November 29th, Comac China delivered the 21st ARJ21-700 aircraft to its customers. Talking about the differences between civil airliners and other aircraft, Ye Chao, deputy director of ARJ21 Division of China Comac Shanghai Aircraft Manufacturing Co., Ltd., has a lot to say: "The independent development of a jet regional aircraft needs to go through the processes of design, trial production, test flight, evidence collection, production, etc. This is not all. To make the aircraft truly commercialized, it must be tested by the market. If the requirements of airlines cannot be met, the cost performance ratio is low, and the experience of drivers, flight attendants and passengers is poor, the mission of the aircraft will not be truly completed. "

  In the process of design and development, the ARJ21-700 aircraft has fully considered the number of seats, comfort and the needs of the aviation market in western China. Compared with similar aircraft, the cabin of ARJ21-700 aircraft has a higher and wider cabin, the cabin height is more than 2 meters, reaching the same cabin comfort as that of narrow-body aircraft, and the cabin height is close to 1 meter, which can provide more luggage space for passengers. The economy of the aircraft is also more prominent, and the engine fuel consumption is low. In order to adapt to the complex geographical environment in the west of China, the ARJ21-700 aircraft pays attention to take-off and climb performance in design, and can take off and land in a short distance, which has a strong advantage in the adaptability of western routes and western airports.

  Although customers’ needs were fully considered in the design and manufacture, when facing the customer representatives seriously, Comac found that there were many details to be perfected. Because, from "product" to "commodity", the difference is not just one word, but also thousands of times of self-improvement and continuous collision with customers.

  In Ye Chao’s view, there were three "self-revolutions" on the sales road of ARJ21-700. "When we sold the plane to Chengdu Airlines for the first time, it was the first time that we delivered the plane to our customers. During the continuous running-in, we found that some problems that we had never thought of were exactly the concerns of our customers. The second time ‘ Self-revolution ’ When the plane was delivered to Tianjiao Airlines. We have changed from serving one customer to serving two customers, which requires us to be more refined in technology and operation specifications. Now we are facing the third time ‘ Self-revolution ’ New customers such as Air China, China Eastern Airlines and China Southern Airlines will put forward more new requirements for our products. In the future, we should look at production from the perspective of creating handicrafts. "

  Since the commercial operation of the ARJ21-700 in June 2016, the optimization and improvement of the aircraft production process has been carried out almost every day. "For example, the pilot’s operation has been greatly modified to reduce the pilot’s workload; In order to reduce the noise in the engine room, the conventional sound insulation cotton material is replaced by metal damping layer and rubber sound insulation material; In order to reduce the airflow noise at the air outlet of the air conditioner, silencers are installed, and there are various optimizations for flight attendants and aircraft maintenance personnel. " Ye Chao said.

  With more and more orders, the mass production capacity of ARJ21 has gradually improved. In 2017, it will produce 4 aircraft, in 2018, 11 aircraft, and strive to produce more than 20 aircraft in 2019. Behind the digital beat is the continuous improvement of the overall efficiency of the workstation and the efficiency of skilled workers. Comac China has continuously promoted the innovation of production management in terms of process technology, on-site management, production operation control and so on. From January to September this year, the batch production rate of ARJ21 aircraft increased by 76.9% compared with the same period in 2018.

  The development of ARJ21 regional jet has accumulated valuable experience for the development of China civil aircraft industry. After the whole process of jet regional aircraft design, trial production, test flight, evidence collection, production, delivery and operation, China has the development capability and airworthiness certification capability of jet regional aircraft, and people have more confidence in the future of large passenger aircraft projects.

  C919: All tests are carried out in parallel, and the test will be prepared for "evidence collection".

  In the avionics system comprehensive laboratory of Comac Shanghai Aircraft Design and Research Institute, researchers are busy, and the indicator lights are flashing on the rows of computers. On the monitors one by one, the program codes pass by in turn, and the C919 aircraft is being tested and verified here.

  Walking into the iron bird test-bed of C919 aircraft, the test-bed in front of us looks like an "iron bird", except that it can’t fly, and its shape and internal structure are basically the same as the real C919 aircraft, so it can be called a simulation aircraft. The integration tests of flight control, landing gear, hydraulic system, etc. are all completed here. After the command is issued from the console, Iron Bird completes the relevant specified actions, confirms and verifies that the system design meets the requirements of product development, and ensures flight safety. The international mainstream aircraft manufacturers have completed the technical verification and technical improvement of related models through the Iron Bird test bed. "In addition, it has another function: when the flight test of the C919 aircraft fails, we can simulate it through the iron bird test bed and find a solution to the failure." Li Tao, director of the construction of the State Key Laboratory of Civil Aircraft Simulation Flight of Shanghai Aircraft Design and Research Institute, said, "At present, we are intensively carrying out the airworthiness verification test of the laboratory."

  Isn’t the C919 plane already empty? What are the researchers still busy with?

  "We are working on the airworthiness certification of the C919 passenger plane, that is, ‘ Textual research ’ . At present, laboratory tests are being carried out here, in addition to on-board ground tests, flight tests, simulator tests and supplier product identification tests. After the success of the R&D test flight of the C919 passenger plane in 2017, it still needs several stages of test flight and airworthiness evidence collection before it can be delivered to the airlines. " Li Tao said.

  In order to ensure the efficient ground test and flight test on board, "in October this year, 105 aircraft completed the first test flight, and the number of aircraft used for flight test will reach 6 in the future, and related flight test work is being carried out in parallel." Nan Guopeng, captain of 105 aircraft of C919, introduced.

  Simulator tests are also being carried out in an orderly manner in Shanghai Aircraft Design and Research Institute. Boarding the C919 passenger aircraft engineering simulator, this equipment looks like a big ball, and its interior is almost the same as the real aircraft cab. Li Tao introduced: "The simulator can undertake the test tasks such as aircraft control law evaluation, cockpit evaluation and safety evaluation. At the same time, it can also undertake the training and training of test flight crews to help pilots understand aircraft performance as soon as possible. "

  It is understood that before the C919 large aircraft is delivered for use, it is necessary to obtain three certificates, namely: type certificate (TC), indicating that the aircraft design is safe and seaworthy; Production license (PC), which indicates that the aircraft manufacturing system meets the requirements and can be produced on a large scale; Single Airworthiness Certificate (AC) proves that a single aircraft is in a safe and available state, which is equivalent to the "driving license" of a car. These work plans will take two to three years to complete. If they go well, Chinese will be able to take a large domestic plane designed and manufactured by himself in the near future.

  In addition to the joy and pride of flying in a large domestic plane, the development of C919 has a long-term strategic significance. It is not a simple product, nor is it an ordinary commodity. The manufacture of large passenger aircraft is known as the "crown of modern industry", which plays a very significant role in driving the civil aviation industry and modern industry.

  From the perspective of aviation industry, with Shanghai as the leader, more than 200 enterprises and nearly 200,000 people from 22 provinces and cities including Shaanxi, Sichuan, Jiangxi, Liaoning and Jiangsu participated in the development and production of large passenger aircraft projects. The China civil aviation industrial chain, value chain and innovation chain driven by the C919 large passenger aircraft have great energy, and at the same time, it has promoted the establishment of 16 joint ventures in airborne systems such as avionics, flight control, power supply, fuel and landing gear, which has promoted the civil aircraft industry in China.

  From the perspective of upgrading the modern industrial level, a commercial aircraft consists of 3 million to 5 million parts. These parts need to be produced by thousands of suppliers, which can promote the group breakthrough of key technologies in the fields of new materials, modern manufacturing, advanced power, electronic information, automatic control, computer and many other basic disciplines. "There are many domestic suppliers involved in the parts of the C919 passenger plane, and the fuel tanks, valves and landing gear equipment of the hydraulic system are all produced in China. Through the C919 project, we have grown together with our suppliers. " Li Tao said.

  At dusk, when leaving Shanghai Aircraft Design and Research Institute, the research building was still brightly lit. In order for the C919 to be delivered as soon as possible and soar in the sky, another night for technicians began … …

  Interview notes

  It takes only 4 hours and 18 minutes to get from Beijing to Shanghai by high-speed train, but it is not necessarily faster than the high-speed train, not counting the waiting time for the flight to take off and queue up. However, this reporter still chose to fly because he had a question in his heart — — When can we get on the big plane made by Chinese himself?

  Not long ago, I was chatting with a friend. When he heard that all the large passenger planes we are taking now are foreign products, his face showed a very surprised look: "What? However, our fighter plane, the National Day military parade is so beautiful, and manned space flight has already sent astronauts out of the earth. How can we buy a foreign plane? " The reporter told him: "It won’t take long. I will definitely bring you back the latest progress when I go to Comac for an interview this time. "

  The plane rushed into the sky and entered the stratosphere. The reporter took out the "Safety Tips" from the front seat pocket and saw that the plane on flight CA1855 was Boeing 787. Thinking of a news I just saw recently, the order for C919 large aircraft has exceeded 1,000. Maybe a few years later, the reporter will watch Safety Tips again, and the models on it will be different.

  With countless questions, I came to Pudong base of Shanghai Aircraft Manufacturing Co., Ltd. and Shanghai Aircraft Design and Research Institute. The reporter finally knew why civil aircraft manufacturing was so difficult. What is carried on it is not goods, nor one or two people, but dozens and hundreds of lives, and there is no room for any safety problems. In addition, the performance requirements of civil aviation aircraft are also very high. During the service period, an aircraft generally has to go through 60,000 flight cycles (take-off and landing) and 90,000 flight hours, with a service life of 30 years or more. Even some seemingly unremarkable parts on the plane must be used stably and safely for decades. In order to compete with the world aviation market, the large aircraft we build must be safer, more comfortable, more environmentally friendly and more economical than others, so as to have a broad market.

  The big plane people are working hard for all this.

  In an interview, the reporter really felt their busyness and dedication. The interview was interrupted several times by phone calls, and the interviewee repeatedly pressed the phone for fear of influencing reporters to ask questions. When a reporter asked a researcher at Shanghai Academy of Aeronautics and Astronautics, "Are there any touching stories in your work?" He smiled and said, "It’s nothing. Everyone usually completes the test task seriously." The colleague sitting on the side couldn’t help it. She grabbed the conversation and said to the reporter, "Our researchers are really selfless. Many technical backbones are in their thirties and forties, old and young. In order to complete the airworthiness forensics work as soon as possible, they basically work overtime every day. You will know when it gets dark." Hearing this, the former researcher who said there was no story was somewhat silent. He said, "Last Friday, I got home after 10 o’clock in the evening and found that my wife didn’t let the children sleep. When I thought about it, I went out early and returned late. The child has not talked to me for a week. " These little details permeate all aspects of the interview, which is moving.

  When leaving the interview, the reporter remembered the 16 Chinese characters hanging on the wall of the C919 assembly workshop — — Long-term struggle, long-term research, long-term hardship and long-term dedication, after the delivery of more than 20 ARJ21, the C919 will also be delivered in the next two or three years, and the CR929 wide-body passenger aircraft jointly operated by China and Russia will also start construction in the next few years.

  Let’s look forward to it. In the blue sky, there are more and more domestic passenger planes.

  Memorabilia of C919 passenger plane

  On January 6th, 2009, China Commercial Aircraft Co., Ltd. officially released the code name "COMACC919" for the first single-channel conventional 150-seat large passenger aircraft.

  On December 21st, 2009, the LEAP-1C engine was determined as a C919 foreign starting power unit.

  On November 15th, 2010, a 1:1 demonstration prototype of C919 large passenger plane was first presented to the public at Zhuhai Air Show.

  On August 24th, 2014, most of the front fuselage of the first C919 large passenger plane was delivered.

  On November 2, 2015, the first aircraft of C919 rolled off the assembly line.

  On April 11th, 2016, the static test of C919 large passenger plane was officially launched.

  On May 5, 2017, the C919 passenger plane successfully made its first flight.

  On November 10th, 2017, 101 aircraft of C919 large passenger plane were transferred to Yanliang.

  On December 17th, 2017, 102 aircraft of C919 passenger plane made their first flight.

  On July 12, 2018, 102 aircraft of C919 large passenger plane were transferred to Dongying test flight base. On the same day, the C919 large passenger plane completed the 2.5g ultimate load static test.

  On December 28th, 2018, the third C919 aircraft completed its first flight at Shanghai Pudong International Airport.

  On August 1, 2019, 104 aircraft of C919 large passenger plane completed the first test flight.

  On October 24, 2019, 105 aircraft of C919 large passenger aircraft completed their first test flight.

  (Reporter Zhang Pengyu finishing)