"The rotors are indeed the same, but can you guarantee that all traces of processing are the same? Is the intensity the same when spinning? Moreover, the upper and lower rotors do not interfere with each other when rotating...... "Liu Yijiu waited for the staff to remove the screws that link the propeller hub to the propeller blades.

Only by seeing something will he confirm whether his guess is correct or not.

Aerospace things are extremely delicate, and sometimes, if a mouse gets into the cabin, it can crash the plane; A sparrow flying high in the air can crash the plane.

Even if it is a small screw, there must not be the slightest carelessness.

If it was really those screws, then this plane crash was too unworthy!

Liao Zhuojing's brows furrowed even tighter, if it was a problem with the screws, this was a production quality accident. The strength of the screws is not good, if it is caused by the design, then the design, proofreading, audit and others have to be responsible. If there is a problem in the production process, the front-line production workers, team leaders, quality inspection, production scheduling and even production workshop supervisors have to be dealt with. Moreover, during the production process, they checked the records of various processes, and there was no problem at all.

If you check from the beginning, you have to start from the production of raw materials, from the raw material formula, material production process, and the production quality of materials......

After Liu Yijiu arrived at the base, that is, since the beginning of 77 years, the entire Ninth Academy began to comprehensively promote the implementation of the seven technical agreements, special personnel, special aircraft, special materials, special approvals, special inspections, special technologies, special cards or special lines. This is to find out from the source after discovering the problem, which link is the problem.

This kind of plan was originally the national military 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 years of turmoil.

The only difference is this. The technical agreement of the seven specialties of this era passed through the hands of Liu Yijiu. It is far more stringent than the 7905 technical agreement that appeared in the original world in 79 and the 8406 technical agreement formulated in 84.

There is absolutely no room for error in the production of military products.

When it is produced, it is only a matter of quality, but when it is used on the battlefield, it is the life of a soldier.

Therefore, Liu Yijiu has used his world to improve it several times, and in light of the current actual situation, it is in line with the current special technical agreement for the production of military products, and it has been popularized in military factories across the country. For the sake of production efficiency and production quality.

"Director Liu. Our production process is so strictly controlled, and the design has also been reviewed layer by layer, how can there be a quality accident? Wang Yueshan rushed to the front, and when he heard Liu Yijiu's words, he was immediately stunned.

If there is a situation like this because of a small quality problem, and the tens of millions they have invested in it are wasted, then there will definitely be a group of people who will be dealt with.

Even he, the director of District 1, will be involved.

Seeing Wang Yueshan with a nervous face, Liu Yijiu shook his head. "Now we can't be sure whether it's a quality accident or not, we can only see things to know, and the biggest problem may be because we think too little about the design. I just thought that when the twin rotors are coaxial, the rotation of the two sets of rotors in the opposite direction will cancel out the torque, and I didn't think that if the design strength of the two sets of rotors is not strictly calculated, they will eventually affect each other......"

Liu Yijiu is the chief designer. He couldn't have been responsible for every screw.

"Isn't there any problem with the previous computer simulation? The strength structure is all the same...... "Liao Zhuojing has not been exposed to coaxial twin-rotors before.

Domestic single-rotor tail rotor helicopters have not even been done. Naturally, there is no energy to get involved with the more technically complex twin-rotor.

Whether it is the coaxial twin-rotor used on the Z-91, or the parallel twin-rotor used in light aircraft. Or the tandem twin-rotors used by heavy helicopters, the country is a blank. The maneuverability of the twin-rotor is much higher than that of the single-rotor tail rotor, and the stability is much stronger, but the technical complexity is too high.

"We did not take into account that when the helicopter rotor rotates at high speed, once the air compressor produces surge, the engine reduces efficiency due to the change of intake flow, and the power transmission changes suddenly, and the two sets of rotors rotating at high speed lose the kinetic energy to do work, driven by inertia, the lower rotor goes up because of the lift force of the upper rotor, and the upper rotor ...... downward because of the pulling force generated when the rotor rotates below."

This was originally a matter of the strength of the helicopter's rotor propeller, but it was transformed into the position where the force was most stressed, that is, the strength of the screws at the junction between the rotor blade and the propeller hub......

If the screws are deformed, the rotor will lose control!

Is that really the case?

I had to wait for the staff to remove the screws from the paddle hub.

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

Hearing this, Liu Yijiu immediately breathed a sigh of relief.

There are no errors in your own analysis.

Wang Yueshan and Liao Zhuojing glanced at each other, revealing a strange and bitter question.

It's a very simple fault, they have been looking here for so long and have not found a problem.

The screws are not unaware that they are damaged, the helicopter has fallen, the blades have been broken, and the position where the maximum force is stressed, it is impossible not to go wrong.

They did not expect that it would be due to the sudden change in the force during the flight, first caused by the deformation of the screws that were not strong enough.

That happens first, and the result is not the same at all, and that's the problem of the mindset.

"Herein lies the problem. No matter what method is used, the strength of the screws must be calculated, and then the force and the influence of the interaction force when the movement of the two rotors changes......" Liu Yijiu gave an order with a serious face.

If you find a problem, you have to solve it.

"In addition, the engine side had to be checked. Why did not there be surge in more than a year of test runs? The results appeared as soon as they went to heaven. This thing has to find out where the problem is, and. Convene all the relevant responsible persons, go back to the technical room for a meeting, and let the technical backbone also listen to it together, they will all stand alone in the future, although this kind of problem is difficult to encounter, but when encountered, we can't let it appear again......" Liu Yijiu said to Wang Yueshan and Liao Zhuojing beside him. "There is also the technical and supervisor ...... of the production unit."

When problems are found, a summary meeting is definitely needed.

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

Technological progress is moving forward after constantly summarizing various failures.

Liu Yijiu found the root of the problem. Whether it is or not, there is no guarantee, only the continuation of production, the continuation of test flights, can be determined. But he can't wait for that time to summarize now, because he has a headache about the thinking patterns of these staff.

Anyone who thinks from a different perspective can actually find problems.

Empiricism kills. This is not for joke.

The experience of single-rotor tail rotor helicopters is used in this, and no one suspects that there is anything abnormal.

Everyone thought that the air surge was happening, and nothing happened.

"We have gathered everyone here today not to hold anyone accountable, but to sound the alarm for everyone. If I have to be held responsible, I, the chief designer, am the biggest person responsible. Because it's something that wasn't taken into account in the design. However. After the accident, it took up to half a month. Countless inspections, encountered these problems. No one analyzes whether this phenomenon is abnormal, or uses the old thinking of the past to analyze the current problem...... Our old way of thinking should be fundamentally changed! Liu Yijiu spoke very seriously to the hundreds of people who were pressed by the black pressure below.

"The research of the Z-7 has indeed brought us a lot of experience, but what we are now engaged in is not a single-rotor tail rotor helicopter like the Z-7, but a twin-rotor with a tail rotor, which is a completely new topic. Here, I would like to ask, why do you still use the research experience and flight test experience of the Z-7 to judge the problems we are encountering, knowing that we have a completely new design and no experience to follow? ”

Liu Yijiu said this, and he was a little stern.

The entire Z-7 research team lowered their heads.

They've been using the experience they've gained to do what they're doing now.

"As early as '77, the Central Committee proposed to emancipate the mind, especially at the 77-year symposium on science and education work, Comrade Xiaoping proposed that we should emancipate our minds, break the previous mode of thinking, better serve the country's four modernizations, and contribute the strength of our scientific and technological workers to the country's catching up with and surpassing the world's advanced level. The task of scientific and technological workers is to produce scientific and technological achievements and talents! Our task is to produce results and improve the level of national defense science and technology! If we cannot change even the most fundamental mode of thinking, how can we promote the development of our national defense science and technology work? "The more Liu Yijiu said, the more angry he became.

These are things he shouldn't have come forward in the first place.

The whole country is now experiencing such a problem.

However, at this time in his Ninth Courtyard, he could not help but bring it up.

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

Otherwise, in the end, he will be tired and tired, and this will still be the case. He has to deal with everything...... (To be continued.) )

PS: This one is a little late, I'm sorry everyone. Today is at least five watches, and we don't guarantee more.

Last night, there was a child named @Brown Sky (real name Hu Songchen) in the book friend group (9512455) who spent a dollar to buy pickle girl experience from Hulu, damn it, do you really think Hulu's pickle girl experience is not worth it? The most shameful thing is that this bastard obviously took two yuan from someone else, but he only gave one dollar to the gourd, and finally said that the plan from the gourd was not good, and seriously despised it......

Selling pickle girl experience, book friends contact gourd, different prices, different plans, tailor-made, chased the price increase, can't catch up is not responsible!