"The rotor is indeed the same, but can it ensure that all the traces of processing are the same? Is the strengths of the rotation the same? Moreover, the upper and lower rotors do not affect each other when they rotate..." Liu Yijiu waited for the staff to remove the screws that link the hub and the blades.

Only when you see something will you confirm whether his guess is correct.

Aerospace things are extremely delicate. Sometimes, if a mouse enters the cabin, it may cause the plane to crash; a sparrow flying in the sky may cause the plane to crash.

Even small screws must not be careless at all.

If it were really those screws, then the plane fell this time would be too unworthy

Liao Zhuojing frowned even tighter. If it was a screw problem, it was a production quality accident. The strength of the screw was not good. If it was caused by design, then the design, proofreading, review and others had to bear the responsibility. If it was a problem in the production process, front-line production workers, team leaders, quality inspection, production scheduling and even production workshop supervisors had to be dealt with. Moreover, they had checked records in various processes during the production process, and there was no problem at all.

If you check again, you have to start from raw material production, from raw material formula, material production process, and material production quality...

After Liu Yijiu arrived at the base, that is, in 1977, the entire Ninth Institute began to fully promote the implementation of the seven special technical agreements, special personnel, special aircraft, special materials, special inspections, special technical cards or special lines. This is to find the problem from the source after discovering the problem, which link has a problem.

This solution was originally the standard of Liu Yijiu's original world. In order to ensure the quality of military components and solve the problem of poor production quality during the ten-year turmoil.

The only difference is that the seven special technical agreements of this era, through Liu Yijiu's hands, are far more stringent than the 7905 technical agreement that appeared in 1979 and the 8406 technical agreement formulated in 1984.

In military production, no errors are allowed.

When it comes to production, it is just a matter of quality. But when used on the battlefield, it is the life of the warrior.

Therefore, Liu Yijiu used his world to improve it several times, and combined with the current actual situation, it is in line with the current specialized technical agreement for military product production, and has been promoted in the entire factory for production efficiency and production quality.

"Director Liu, our production process is so strict and the design has been reviewed layer by layer. How could a quality accident occur?" Wang Yueshan rushed to the front. Hearing Liu Yijiu's words, he was immediately stunned.

If this happens because of a small quality problem, and the tens of millions of investment they have invested in it will definitely be dealt with.

Even the director of District 1 will take care of it.

Seeing Wang Yueshan with a nervous look on his face, Liu Yijiu shook his head, "I can't tell if it's a quality accident now. I can only see things. The biggest problem may be because we considered too little during design. I just thought that when the two rotors rotated in the opposite direction when the two rotors rotated in the opposite direction, which would offset the torque. I never thought that if the design strength of the two rotors was not strictly calculated, they would eventually affect each other..."

Liu Yijiu is the chief designer, so he can't even take charge of every screw.

"Isn't there any problems with the previous computer simulation? The strength structure is the same..." Liao Zhuojing had never been exposed to coaxial double rotors before.

Even a single-rotor tail rotor helicopter in China has not been able to handle it, so naturally there is no energy to target the twin-rotor with higher technical complexity.

Whether it is the coaxial twin rotor used on the 91, the parallel twin rotor used in light aircraft, or the longitudinal twin rotor used in heavy helicopters, there is a blank in China. The operability of the twin rotor is much higher than that of the single rotor tail rotor and has a much stronger stability. However, the technical complexity is too high.

"We did not consider that when the helicopter rotor rotates at high speed, once the air compressor surges, the engine will reduce efficiency due to changes in intake air flow, and the power will suddenly change when it is transmitted. The two rotors rotors at high speed have lost the kinetic energy to do work. Driven by inertia, the lower rotors are up due to the lift of the upper rotor, and the upper rotors are down due to the pulling force generated when the lower rotors rotate..." Liu Yijiu said his inference.

This was originally a matter of the strength of the helicopter's rotor blade, and then it turned into the position where the most stress was applied, that is, the strength of the screw at the connection between the rotor blade and the hub...

The screws will cause the rotor to lose control

Is this really the case?

I can only wait for the staff to remove the screws on the hub.

In a few minutes, a technician in his forties ran to Liu Yijiu and others sweating profusely, reporting helplessly: "Leader, the screws at the link between the hub and the blades have been completely damaged and cannot be removed..."

Hearing this, Liu Yijiu was relieved.

There are no errors in my own analysis.

Wang Yueshan and Liao Zhuojing looked at each other, revealing a strange and bitter problem.

It was a very simple failure. They searched here for so long, but they didn't find any problems.

They didn't know that the screws were damaged, the helicopters fell down, and the blades were broken. It was impossible to have no problem with the position where the most stress was affected.

However, they did not expect that it would be because the stress condition suddenly changed during flight, and the changes were caused by the deformation of the screws with insufficient strength.

If that happens first, the result will be different at all. This is the problem of thinking patterns.

"The problem is here. No matter what method is used, the strength of the screw must be calculated, and then the stress conditions and the influence of the interaction force during the movement of these two pairs of rotors..." Liu Yijiu issued an order with a serious expression.

Once the problem is found, the problem must be solved.

"In addition, the engine must also be inspected. Why did there be no surge in the test run for more than a year? As a result, it happened as soon as it went into the sky. This matter must be found. Moreover, all the relevant persons in charge were called back to the technical room for a meeting, so that the technical backbones could listen together. They will be alone in the future. Although this kind of problem is difficult to encounter, if we encounter it, we cannot let it appear again..." Liu Yijiu said to Wang Yueshan and Liao Zhuojing beside him. "There are also the technology and supervisors of the production unit..."

If you find a problem, you will definitely need to hold a summary meeting.

This is a habit and tradition that any research team will have.

Technological progress means moving forward after constantly summarizing various failures.

Liu Yijiu found the root cause of the problem. It is impossible to guarantee whether it is true. He can only continue to produce and continue to test flights to confirm. But he can't wait for that time to summarize it because he has a headache about the thinking patterns of these staff.

Anyone can actually find problems by thinking from a different perspective.

Empiricism kills people, and this is not just a joke.

No one doubts about the abnormality of using the experience of single-rotor tail rotor helicopters.

Everyone thinks that air surge phenomenon has happened nothing.

"Today, everyone is called here not to hold anyone responsible, but to sound the alarm for everyone. If we have to hold them accountable, I, the chief designer, are the biggest responsible person. Because this is a problem that has not been considered in the design. However, after the accident, after half a month, countless inspections, no one has analyzed whether this phenomenon is abnormal, or used the old thinking of the past to analyze the current problems... Our past thinking model should have fundamentally changed." Liu Yijiu spoke very seriously at the hundreds of people underneath.

"The research on the 7th of the 7th has indeed brought us a lot of experience, but what we are doing now is not a single-rotor tail rotor helicopter like the 7th, but a twin-rotor tail rotor. This is a brand new topic. Even internationally, only the Soviet Union is currently engaged in research on coaxial twin-rotors, but not with a tail. Here, I would like to ask, why do we know that this is a brand new design and have no experience to follow. Are you still using the previous research experience of the 7th of the 7th and the test flight experience to judge the problems we are facing now?"

Liu Yijiu said that this place was a bit harsh.

The entire research team of 7th all lowered their heads.

They have always been using the experience they have gained before to carry out their current work.

"As early as 1977, the central government proposed to emancipate the mind, especially at the symposium on science and education work in 1977, Comrade Xiaoping proposed that we should emancipate the mind, break the previous thinking mode, better serve the country's four modernization construction, and contribute the strength of our scientific and technological workers to the country catch up with the world's advanced level. The task of scientific and technological workers is to produce scientific and technological achievements, and our task is to produce results. To improve the level of national defense science and technology, even the most fundamental thinking mode cannot be changed. How can we promote the development of our national defense science and technology work?" Liu Yijiu said the more he became more and more popular.

He shouldn't have stood up these things.

This is the problem that is encountered in the whole country now.

However, at this time, in his Ninth Court, we had to mention it.

During this meeting, the main leaders and technical leaders of several other districts participated. Liu Yijiu took this matter as the starting point and sounded the alarm for other units.

Otherwise, he would be exhausted in the end, and this would still be the case. He would have to deal with any problem... to be continued.

ps: This is a bit late, I’m sorry for everyone. Today is at least five updates, and we won’t guarantee that there will be more.

Last night, there was a boy named Brown Sky, whose real name Hu Songchen, who spent one dollar to buy girls from Hulu. Damn, do you really think Hulu’s experience in picking girls is not worth it? The most shameful thing is that this bastard obviously cheated two dollars from someone else, but he only gave Hulu one dollar. In the end, he said that Hulu’s plan was not good and he seriously despised him...

Experience in selling girls, book friends contact the gourd, different prices and different plans, tailor-made, after catching up, you can't get the price increase, but you can't get it.
Chapter completed!