"Where did you get this technology? If we just do our own research, it is impossible to figure it out in just a few years, right? The variable wing system is not a simple project! Liu Yijiu is really interested in the source of technology.

The Republic's research on the variable wing system can be traced back to the sixties, but twenty years have passed now, and there has been no breakthrough at all.

It is precisely because of this reason that the variable swept wing fighter developed by the Hongdu Aircraft Factory, the only one in China that has the production of strong attack aircraft, was dismounted!

This is a technical problem that the republic did not solve in the eighties.

It can't be solved by Zhu Houdao and others!

When Zhu Houdao heard Liu Yijiu ask like this, he couldn't help but stop talking.

"Say, no matter where the technology comes from, I won't pursue it." Perhaps, these technical sources are somewhat sensitive.

Hearing Liu Yijiu's assurance, Zhu Houdao said, "In the process of improvement, we have had a lot of exchanges with the comrades of the Hongdu Aircraft Factory, they have experience in the design of the strike aircraft, and it is also more than ten years ago that after the country got the MiG-23MC, Comrade Lu Xiaopeng, the chief designer of the Qiang-5, began to prepare for this aspect. In 80, the third-level ministry issued the task of developing the strong six......"

Hongdu Aircraft Factory, in fact, is the Nanchang Aircraft Factory, which is one of the earliest aircraft factories in the Republic, and the Qiangwu is also the first independently developed jet attack aircraft in the Republic. For this aircraft factory with a mission, Liu Yijiu did not have too much contact.

Mid-fifties. China has established diplomatic relations with Egypt, and Egypt had a very good relationship with the Soviet Union. It has always been equipped with a large number of Soviet weapons and equipment.

Egypt was the first Arab country to support the cause of Pakistan, at the time of the formation of the Pakistan Liberation Organization. It was supported by Egypt.

Although the current relationship between the two sides has not been restored because of the peace talks between Egypt and Israel, with such a relationship in it, the relationship between China and Egypt has never changed too badly. In the sixties, Egypt broke away from the Soviet camp and joined the Western camp, when China exchanged a batch of weapons and equipment from Egypt for several MiG-23MC fighters, thus starting China's research on variable swept wings.

Liu Yijiu knows this.

But he doesn't believe that results can be achieved now.

If only there was a breakthrough now. The strong six will not be dismounted in the late eighties.

After all, the main reason for the strong six dismounts is that the variable sweep wing mechanism is 12% heavier than the MiG-23, which makes the already small bomb load and fuel load. It also seriously affected the combat radius, as well as the flexibility of the fighter. Another problem is the control system of the variable sweep wing mechanism.

These systems are definitely not problems that can be solved by imitation.

"We exchanged the control technology with them with the variable sweep wing mechanism, and we cooperated more in this regard. And after having the technology of the F14 for reference. This has a very big effect on their research...... "Zhu Houdao is still a little worried that Director Liu will be angry.

What he didn't expect was that Liu Yijiu didn't get angry, but nodded, which made him breathe a sigh of relief.

Although he wanted to ask Liu Yijiu if he was angry about anything, he finally held back.

"In terms of technology, not any one unit can solve it alone. It's a good thing to be able to cooperate with our brother units, and we can communicate with each other. Progress together. Mountaineering, that's unacceptable! Liu Yijiu's words solved the contradiction in Zhu Houdao's heart.

That sounds good, though. But most of the good things in the Ninth Academy are kept by themselves, and there is no such thing as Liu Yijiu saying that they communicate with each other and make progress together.

The main business of the Ninth Academy is technical output and standard output.

The impact on domestic units is very large.

The technology of Hongdu Aircraft Factory is more useful to them, but their control system has a more important role for Hongdu Factory.

According to the previous practice, they naturally had to use money to buy it.

However, although the Hongdu Factory now has the task of developing the Qiangliu fighter, it does not have too much money to purchase technology from the Ninth Academy.

"Variable skimming-wing aircraft are technically complex and require more time and effort to study. Being able to get the technology from our brother units, and then develop our own technology from them, such a model should be promoted, of course, the cost issue must be considered......" After Liu Yijiu finished speaking to several other people, he didn't say anything more.

The F14 has been disassembled and assembled an unknown number of times, and the engine has been disassembled.

On the workbench, both engines lay on it.

From the outside, there is simply no way to see the structure inside these engines.

After all, it's assembled layer by layer.

"In the maintenance department, our people are replacing the parts of the engine, Director Liu, you can see the ...... over there" Qi Hai knew that Liu Yijiu wanted to see the engine, and the one in front of him had already been repaired, and if it was disassembled again, it would waste a lot of man-hours.

"Let's see." Liu Yijiu also knew that it was necessary to understand the internal structure of the engine to see where the technical failure appeared and what caused it.

"According to our fault analysis, the main reason is that the fan strength in the high-pressure area is not enough, and on the other hand, the lubrication is not in place, which causes the throttle to be too large or too small, and instantaneously changes the oil change inside the engine combustion chamber......" Qi Hai took Liu Yijiu to the maintenance department next to him, and introduced to Liu Yijiu.

Professional things, others are confused, but Liu Yijiu is very serious about this.

For convenience, a workshop for engine repairs was built next to the parking room.

This workshop was built for the Turbofan Eight.

The workshop is not big, only less than 200 square meters, and when Liu Yijiu and a few people arrived, there were more than ten technicians wearing the work clothes of the Ninth Academy who were busy inside.

The turbofan discs at all levels were disassembled, and the various parts of the silver-gray were polished very smooth, faintly reflecting the surrounding images under the light.

If you just look at the surface and don't know the inside story, you will definitely be amazed by the manufacturing process of the republic.

Liu Yijiu didn't speak, many turbofan discs of the entire engine were disassembled, carefully inspected, the cracked turbofan disc was put aside alone, Liu Yijiu took it and walked forward, with the help of the staff to observe the cracked turbofan disc.

"This didn't happen during engine testing on the ground platform?" Liu Yijiu saw that on a group of turbine disks with a gradually smaller diameter, the smaller the blades, the more obvious the cracks at the roots.

Obviously not strong enough!

Since the intensity is not enough, why is it only found at this time?

Or did you find out why it continued?

This is mounted on an aerial platform, and an F14 is 80 million dollars!

Qi Hai would not fail to understand such a thing.

So, there must be something inside here.

"When we experimented on the ground platform, we didn't find this problem. Our engines are designed to have a minimum service life of more than 4,000 hours. There is no problem with running on the platform for 6,000 hours in a row, and it is precisely because of this that we are ready to use it on the air platform for testing, as long as there is no problem on the air platform, this can be provided to our Panda fighter and the Double Three Project......" Qi Hai sighed.

He also didn't understand where the problem was.

He has been following since the first engine prototype was produced.

"If the strength is not enough, we have calculated it, but if the strength is not enough, we can find it on the ground platform......"

Liu Yijiu listened patiently.

At the end of the day, ask if there is a new impeller to replace.

Comparing it with the new impeller may be able to identify the problem.

Qi Hai also told Liu Yijiu that they had compared countless times, and when they were not installed, they were even installed on the ground for experiments, and as soon as they were installed on the plane, there would be problems.

At first, I thought that there was a problem with the oil circuit or a problem with the control system, but these were all after countless technical analyses and improvement work, and finally this is the result.

If the pilot hadn't risked his life to glide the fighter back to the airport using the control wing control, this expensive F14 used for testing would have fallen a long time ago.

"Maybe the problem is in the processing." After Liu Yijiu compared, he found that all the roots of the impellers were polished manually.

"It shouldn't be! We thought about it at first. In the end, it improved, but it is still the same. As long as you don't use afterburner, there is no problem......"

"When you turn on afterburner, the temperature is higher and the pressure is higher, which is more demanding on the material, don't you know? When grinding, the traces of the roots are obviously inconsistent, Lao Qi, haven't you noticed that on these impellers, there are no rules for the cracks in the roots? Liu Yijiu pointed to the very subtle cracks on it and said.

On the impeller that the worker next to him was holding, there were three blades with a crack at the root that was thinner than a hair.

These cracks are not evenly distributed along the direction of the roots, showing irregular marks.

"But we all use the best grade 9 fitters for grinding......"

"Our grade 9 fitters have never been exposed to the processing of such precision special-shaped parts before. The Americans manufacture such engine parts using CNC machine tools, and they are special CNC machine tools with very high precision. The Soviet Union used special planes, while ours used manual ones. Dozens of blades, any position has to be kept the same, do you think our workers can do this? "It's not that Liu Yijiu doesn't believe in domestic skilled workers.

It's that the requirements for workers are too high!

(To be continued.) )