3 hours, AG600 aircraft 1003 aircraft assembly site of a "night battle"

At 20:30, the aviation industry near the runway of Zhuhai Airport flew to the factory area of South China Company, and one after another of overtime trucks started one after another. Without the taxiing and landing of the airport runway during the day, the noisy dialogue sound of the walkie-talkie from the brightly lit 205 assembly plant is particularly "harsh", and one of the three most important tasks of the South China company this year is being carried out - the final assembly and production of the AG600 aircraft 1003 aircraft.

"Everybody's in place, now start pressurizing." Instructions began to be issued on the intercom, and tonight, the third pressurized cabin airtight inspection test carried out by the 205 plant began.

In order not to affect the progress of the final assembly work during the day, the air tightness mapping test is generally carried out at night. In the past year, in the face of the intense and arduous annual assembly task, the "night battle" will be staged in the factory building of the South China Company basically every day. "The results of the last mapping test have basically met the requirements, and today we will see if the effect can be better." The teacher who cooperated with the test on the spot said.

Pre-test preparations begin. Li Xiaowen, the 41st station chief, assigned personnel positions and distributed tools. Since the first boost was only up to 11 kPa at most, the crew could go to the bottom of the ship under the pressurized floor of the through cabin to observe the pressurization. Li Xiaowen said to the author: "It is very dark underneath, it is not easy to stand, it is easy to commit claustrophobia." "When I really went down to the bottom of the ship, it was pitch black inside, and the flashlights in the hands of the masters became the only source of lights." Since the aircraft is still in the final assembly stage, the taste of glue is relatively large, and the unique bottom shape of the AG600 aircraft makes it difficult for everyone to settle down.

After the evacuation of the ducts and lamps in the cabin, at 21:10, the first pressurization began and the underside of the ship began to inflate. "After the aircraft pressurization cabin starts to be pressurized, the air at the bottom of the ship will be reduced, and the inflation at this time is to ensure our oxygen safety." The master next to him explained. After the bottom of the ship was inflated for 8 minutes, the sound of pressurization began to be heard from the intercom, and the test officially began.

"Now the pressure value is 2 kPa" "Now the pressure value is 4 kPa"... The voice of Zhu Xiaoliang in the assembly center reporting the pressure value in real time over and over again came from the walkie-talkie. At 21:26, after the pressure value reached 11 kPa, the pressure retention began, and the masters responsible for the bottom of the ship, the outside nose radar cabin, the left and right hatches, the 34-frame hatches, the main landing gear fairing and other points began to check the air leakage points one by one.

"Due to the complex riveting relationship, where there are more rivets in general, the lamination surface and the filling angle sealing are not very good, and the possibility of air leakage is very large, which requires careful inspection." Li Xiaowen said. As he was speaking, the master next to him found the air leakage point. "The last time the test of the air leakage place is much better, this time there are still some places where there is a leakage phenomenon, mark the place of the air leakage."

At 21:40, the pressure relief was completed in the cabin, and everyone returned to the ground, and the first pressurization was completed. As soon as the hatch opened, the masters used putty strips to temporarily plug the leak points they had just found, preparing for the second pressurization.

"After the cabin is full of pressure, people inside are equivalent to diving to a depth of 4 meters, which will feel very uncomfortable, so we can still enter the bottom of the 11-capa boat the first time, and the second time we have to pressurize to 43.6 kappa, people can't go in." The on-site master explained.

Wang Bin, the captain of the on-site commando team and the deputy general manager of the company responsible for the assembly site, said to the author with a smile: "Although the bottom environment of the ship is relatively closed, the masters who have been to the wing fuel tank know that it is really stuffy and panicked." ”

During the conversation, the second pressurization has begun, at 22:03. The value of the pressure gauge continues to rise, 11 kappa, 22 kappa, 33 kappa, "continue to pressurize, target 43.6 kappa", this boost is divided into 4 times, each time after reaching the specified pressure need to hold the pressure for 2 minutes. Unlike the previous trial, the closer this time it is to the target pressure value, the slower the pressure increases.

"The pressure reached 43.6 kappa, now start holding the pressure for 5 minutes." The experiment reached the most critical moment.

"The result?" Yan Ping, a designer in the structural department, also ran to the pressure gauge and asked anxiously. As the chief designer of the pressurized chamber airtightness inspection, he pays more attention to the results of the test than anyone else.

"The total leakage is stable at 152 kg/h."

"What is required in the document is that the maximum leakage at 25°C is not more than 460.3 kg/h, most aircraft will be controlled at about 280 kg/h, and our aircraft are now far below average." Saying, Yan Ping took out his mobile phone, "Although the results of the last thorough test were also in the document standard, they just reached the average level of ordinary aircraft." The curve slope of the test data this time is significantly lower than the result of the previous time, indicating that the effect of this time is very good. ”

"The door seals are also very powerful. The inner side of the sealing strip is designed with ventilation holes, which is simply that the air pressure in the inner cavity of the sealing strip increases with the pressure in the cabin, and the pressure difference with the external environment is getting larger and larger, and the sealing strip will have a tightening effect, and the air tightness effect will be better and better. Zhang Hao, head of hatch design and designer of the structural department, said proudly: "At first, everyone did not believe that why low pressure leaked air and high pressure did not leak." Today, after the cabin pressure is higher than 25 kappa, the air leakage point of the hatch has reached a normal airtight state, and the test results have proved that our design is not a problem. ”

"Although these 3 times are only a thorough test, seeing the test results are so good, we have a lot of confidence in the formal test after the acceptance of the equipment." Yan Ping said.

Everyone was relieved to see that the results of the test were successful.

At 23:30, the pressurized chamber was relieved and the hatch was opened again.

"Everybody resume the scene." "It's early today, we did it until the early hours of the morning in the last test." Ma Jianming said. The director of the assembly center of the "post-85s" is the person who appears on the scene the most times. He is the commander of each final assembly scene "night battle", and he is also the "trumpeter" of the annual final assembly mission impact. Everyone has seen the back of his sweat-wet overalls at the scene, seen him holding a walkie-talkie to direct the disassembly and hoisting equipment on the spot, and also seen his busy figure at night, and even seen him care about the workers on the spot and run before and after everyone. With him on the production site, all tasks can be arranged in an orderly manner.

After cleaning up the scene, calm returned to the early morning of the next day. In the early morning, this group of "loveliest people" at the final assembly site will appear again on time in the 205 factory.

This "night battle" is over, and we know that the next "night war" is coming.