Chapter 319: Foreign body in air intake, hidden danger solved! (Added update 45 for the alliance leader [the free agent])
Actually, Chang Haonan doesn’t have much to say.
Now that the problem has been identified, the next step is to solve the problem.
Aircraft manufacturing is an extremely complex industrial process. Even more than 20 years later, many steps are still highly dependent on manual operations. In this process, some broken rivets and metal debris are produced. Metal legacy is almost inevitable.
But under normal circumstances, according to regulations, parts should be inspected and cleaned before the end of each step in the final assembly process. This step should be able to remove most foreign matter on the surface of the workpiece. Secondly, even if there are some fish that have slipped through the net in some deep holes that are difficult to detect and clean, they cannot easily get into the air intake.
As for the fact that prototype No. 1001 did not check and clean the inside of the intake duct before delivery...
Chang Haonan glanced at the 132 factory representative who lowered his head and did not even dare to breathe out, and felt that this The possibility is probably relatively low.
Given the importance of Project No. 10, all inspection processes must be repeated many times during the final assembly process.
Besides, even if we only judge from logic, if the quality management of Factory 132 can be so outrageous, then similar accidents should have happened long ago.
Thinking of this, Chang Haonan quickly ran through the aircraft manufacturing process he had learned from Factory 112 in his mind, and then stood up.
As a result, before he could speak, and no one knew who started it, there was a burst of applause in the conference room.
It was sparse at first, but almost instantly it became like a flood.
Chang Haonan raised his hand and pressed it down, but it had no effect.
He noticed that the eyes of the participants, especially those from the test flight station and assembly workshop, had changed significantly compared to the previous days, and even compared to this morning.
That's the difference between "hearing that someone is awesome" and "realizing that someone is really awesome".
It wasn't until about a minute later that the applause finally subsided.
“First of all, judging from the content of the inspection report, the metal debris attached to the end of the inlet and the engine blades can basically be determined to come from the drilling and nailing process during the riveting process.”
Although this is a problem that everyone is already aware of, when it was formally summarized at the meeting, many people still felt a little bit in their hearts.
Especially Xue Chishou.
As the chief engineer, he will inevitably be held responsible if such a large quality defect occurs during the production and manufacturing of the prototype.
Of course, he has also been mentally prepared for this.
However, just when Xue Chishou was ready to criticize himself, Chang Haonan immediately changed the subject:
“But I think this is not a case of production responsibility or quality. The main reason for the problems caused by the insufficient implementation of detection rules should be at the technical level. "
This sentence made many people feel a little calmer.
“Compared with the various types of J-7 aircraft produced by Factory 132 in the past, Project 10 is unprecedentedly complex in terms of process and design, and the standards for production and testing cannot be improved overnight, nor can it be improved overnight. That is to say, many operating procedures and production regulations that were not problematic before may be problematic now.”
"So, in view of the current situation, I think there are two tasks that should be carried out immediately. One is to conduct a thorough inspection of the aircraft and conduct a thorough inspection of the excess objects that accidentally fell into the body cavity during the skin riveting process. To fix the leak, the second is to comprehensively inspect the design of the aircraft and find out where the foreign matter in the aircraft cavity entered the air intake."
After his brief speech, Chang Haonan returned to his seat.
Although he was invited to serve as a consultant for Project No. 10 and has considerable authority and say in the project, he is not an internal staff member of the 611 Institute and the 132 Factory after all, and he is sure about the more specific issue of responsibilities. Can't say much more.
That is a matter for their organizational department.
“Let me add two more points.”
Xue Chishou pulled the microphone in front of him slightly closer to himself,
"No matter what the cause of the problem is ultimately found out, the main responsibility will be borne by me, so everyone should not have too much psychological baggage at work. , In addition, after the investigation is completed, corresponding production rules and regulations should be formulated according to the characteristics of the J-10 to ensure that no excess objects are allowed to enter the body cavity in any process of production. "
" Dismissal!”
After clarifying the next tasks and taking the reassurance given by Xue Chishou, the haze of the failure of the first test run was finally eliminated, and everyone quickly started the follow-up work according to the arrangements at the meeting. . Factory 132 turned around and directly launched a "Quality Culture Month" construction activity. Not to mention, Factory 611 conducted inspections on the air inlet design faster than Chang Haonan thought.
On the morning of the third day, he had just finished breakfast and came to the office when he received a call from Yang Wei:
“The connection between the air inlet and the body cavity has been found.”
< br>"So fast? Wait for me to come right away."
A few minutes later, Chang Haonan found Yang Wei buried in a pile of drawings in a design room——
Because No. 10 The design of the project began in the early 1990s, and the basic design was completed before Chang Haonan was reborn, so naturally he did not wait for the opportunity to use digital design technology.
Now the 611 Institute has begun to organize some manpower to absorb relevant experience from the 601 and 603 Institutes, but this kind of work is destined to be impossible to complete in a short time.
So I still have to slowly turn over the paper drawings.
"Chang Gong, I confirmed several times yesterday that the J-10's air inlet has no physical connection with the cavities such as the wings and the fuselage frame. Even if there are foreign objects remaining in these parts, it is absolutely impossible. was sucked into the air intake, so I changed my mind this morning, look here."
Yang Wei pointed to several places near the entrance of the air intake.
“The binary three-wave system adjustable air inlet has several spherical one-way valves in it to ensure effectiveness and reliability under various working conditions. The manufacturing process of this component is to combine springs, brackets and The valve closes directly after being installed inside the casing, which is a part that cannot be disassembled after it is offline.”
"I asked the manufacturer responsible for manufacturing this valve and learned that they used to use a simple kerosene flushing method to clean it. However, after analysis, this method is not good at removing foreign matter that may remain inside the housing."
“Under normal circumstances, this valve should be closed during engine operation, but if something is stuck in the bearing part, it will cause poor reset. In this case, the strong negative pressure inside the intake duct will It is very likely that the metal foreign matter inside will be sucked out!"
Chang Haonan took several design drawings of the air inlet and the spherical one-way valve, spread them out on the table and observed them carefully for a few seconds.
Then he remembered that he had seen similar structures before.
“Wait a minute... shouldn’t this thing have a special cleaning spindle?”
"Special mandrel?"
Yang Wei was stunned:
"They never mentioned this. They said it was a direct high-pressure fluid flushing method."
" Hmm..."
Chang Haonan realized that the cleaning tool he had seen in his previous life should have been made during the process of solving the problem after the J-10 failed two consecutive test runs.
Fortunately, the structure is not complicated, and he can easily come up with the design drawings by working backwards on site.
"Do you have a computer with drawing tools?"
"There is one next door, I will take you there."
At noon that day, Chang Haonan put a A printed drawing was given to Yang Wei.
“The principle of this equipment is as shown in Figure 2. Before cleaning, use the mandrel shown in Figure 3 to push it in, push the valve 10 open, and then use reverse pressure to flush..."
< br>
Yang Wei listened to Chang Haonan's introduction and was stunned.
After a long time, he took the drawings from the latter and said with emotion:
“I used to think that I was somewhat competent in engineering.”
"Now it seems that we still have to continue to pursue progress..."
(End of this chapter)