Back in 1978, I was admitted to Northwestern Polytechnical University.

Chapter 384: Do the Q-5 and IDF use the same engine?

Sichuan Province, wind tunnel cluster.

“This data… is clearly inappropriate!” The head of the wind tunnel looked at the person next to him with some curiosity: “How could your design from Northwestern Polytechnical University have such a problem? The fins and air intakes here will generate shock wave interference after Mach 1.2, greatly increasing drag. After Mach 1.5, the drag is so great that it’s like a wall… However, even the most advanced medium-thrust engine in the world right now would probably only be able to fly at Mach 1.4 at most…”

Professor Sha's student, Zhu Yongguang, scratched his head and said, "Well, well... I don't know either. This is the shape design that my teacher values ​​the most. He told me that as long as the drag increases rapidly in the supersonic range, then there's no problem."

"Hmph, it's not just a drag problem. The vertical stabilizer is also problematic; its position is too forward, resulting in insufficient vertical torque. This isn't an issue in the subsonic range, but in the supersonic range, the aircraft's vertical stability drops rapidly, causing problems when turning..."

"Oh, that would be even better."

The person in charge was even more surprised: "So, you designed it this way on purpose?"

Designing a bad aircraft is easy, but designing an aircraft that works fine in the subsonic region but fails miserably in the supersonic region is a real test of a designer's skills!
There is no supersonic wind tunnel on the other side of the ditch, not even a decent one. At most, they can test subsonic speeds. For supersonic performance, you need to go to the United States to test it. The problem is, without hiring an American team to help with the design, why would they test a wind tunnel for you?

They can only trust the results from the East!

In this way, even if they manage to get it back, it will only be a subsonic trainer aircraft, which cannot be used as a supersonic fighter jet at all. In particular, their most important combat mission is air defense interception, which requires supersonic flight performance the most.

Later, when they had the F-16 and the Mirage 2000, after comparing them, they found that the Mirage 2000 was actually the best. Its supersonic interception capability was far superior to that of the F-16, which is also the advantage of the delta wing.

Now, trainer aircraft can be provided, but fighter jets... hehehe.

"It's not difficult to make this improvement; we just need to move the air intake and the vertical stabilizer backwards," the person in charge said.

"Yes, if we were to build a similar aircraft ourselves, we would definitely make the modifications in this way. However, our customers do not have the capability to do so. Even if they did make the modifications, the change in shape would alter the entire flight control law, making it almost like a complete redesign. Moreover, we would also tamper with the subsequent structural design, anticipating that it would disintegrate in mid-air at 7g."

Not only can it not fly at supersonic speeds, but even dogfighting within the subsonic and high subsonic ranges is dangerous. Such an aircraft... well, let's just say it's not safe.

The person in charge felt a chill. Last time, when he designed an airplane for David, it turned out like this. This time, he didn't know who he was trying to screw over.
You'll understand later. For now, don't ask questions you shouldn't ask.

A week later.

Across the ditch is the aviation development center.

"Everyone, the design is complete!" Huang Xiaozong said excitedly. "Take a look and see if the performance meets the standards."

Xing Youguang opened his eyes wide and looked at the beautiful shape on the design drawings.

"The large convex shoulder of the strake indicates that it has a good effect on generating vortices. With such a shape, its high angle of attack performance is bound to be good. Needless to say, it can fly at 45 degrees, let alone the 40 degrees we require."

Xing Youguang began to analyze.

"The leading-edge extensions, wings, and fuselage are perfectly integrated without any transition. This is a first-class blended wing-body design. The air intakes are located below the leading-edge extensions, on the two sides, and are only blocked during dives, at which point the engine's power is no longer needed."

"The all-moving horizontal stabilizer design is also very good. The vertical stabilizer is positioned a little too far forward, but advanced third-generation fighters are all designed this way, and it's a trend."

"So, this design is good?"

“That’s right, the design is excellent!” Xing Youguang said. “Next, we need to make a wooden model based on the blueprints and test it in the wind tunnel.”

After saying that, he stood up and couldn't wait to get to work.

Three days later.

"The wind tunnel data is amazing, practically perfect! Since the subsonic performance is so excellent, the supersonic performance must be outstanding as well. Next, we should proceed with the detailed design..."

Xing Youguang paused for a moment before continuing, "I hope that the entire structural design of the aircraft can also be handed over to the East. They can probably design it in a month or two. By then, we might even be able to assemble a prototype!"

The design capabilities of Northwestern Polytechnical University are so impressive that they are astonishing. If this kind of work were done by the original partner, Northrop, it would probably take three to five years!

"Yes, absolutely. We can just spend more money. I heard that the engine improvements are going smoothly, and the front three-stage fan blades have already been designed. Their supercomputer... is really powerful. I wish we had a computer like that!"

Everyone felt a pang of envy, always thinking their skills were superior to those on the mainland, but now, they had no choice but to admit it!

Huang Xiaozong nodded: "Yes, their aircraft design capabilities are truly impressive. However, we don't need to be too envious. We also need to develop our electronics industry. In the future, we will surpass the East!"

"Report, their quote is out. If we move on to detailed design, they'll ask for $100 million in R&D costs."

The price has skyrocketed!

The wind tunnel is just the external shape; the detailed design that follows is where the real skill comes in. The more detailed the finite element analysis, the more money it costs. For Northwestern Polytechnical University, it might just be a matter of paying more for electricity, but for design teams from other countries, it means a huge workload.

A price of one hundred million US dollars is reasonable.

"Okay." Huang Xiaozong nodded. They had already gritted their teeth and paid the five hundred million US dollars for the engine's research and development, so this hundred million was nothing!

Northwestern Polytechnical University, Datang Corporation.

“Liangzi, the $100 million R&D funding has arrived. It’s really easy to make money from this island nation. But… I always have a bad feeling that something’s wrong.” Qin Baomin looked at his son and said with some concern.

Dad did a great job; he actually started to have a premonition!
Qin Liang smiled and said, "Dad, don't worry, what could possibly go wrong? It's a project introduced by my uncle's family, how could there be a problem? Brothers fight together, fathers and sons go to war side by side. If you can't even trust my uncle's family, who can you trust?"

“Your uncle is definitely fine, but… I always feel that there’s something wrong with Da Ming’s wife.”

Fortunately, the old man is making rapid progress! Qin Liang is very satisfied.

"Yes, Dad, don't worry, I'll have someone keep an eye on things, there won't be any problems."

"it is good."

Knock knock! Just then, there was a knock on the door.

"President Qin, Mr. Qin Ming and Keiko Waseda have arrived. I have led them into the reception room."

"Okay, let's go take a look."

living room.

"Liangzi!" Qin Ming's eyes lit up when he saw Qin Liang: "Liangzi, the technology at Northwestern Polytechnical University is so advanced! I hope to pursue my doctorate at Northwestern Polytechnical University!"

"Well, I've already asked the school. You can pursue a doctorate, but... you have to acknowledge your ancestral roots, transfer your household registration here, and settle in mainland China from now on. Any need to leave the mainland will require you to submit a report in advance."

"Yes, I can accept it!" Qin Ming's eyes were full of anticipation.

"And..." Qin Liang glanced at Waseda Keiko and said somewhat embarrassedly, "Your family members all need to undergo political vetting. As far as I know, it's very difficult for foreigners to pass the vetting process."

Keiko Waseda's expression changed instantly. Fueled by her encouragement and the allure of the technology here, Qin Ming desperately wanted to pursue a doctorate at Northwestern Polytechnical University, but... he couldn't abandon his own path just to get a doctorate!

Keiko Waseda also hoped to obtain a continuous stream of intelligence from Northwestern Polytechnical University through Qin Ming!
Now, Qin Ming's condition for joining Northwestern Polytechnical University is that he breaks up with her?
No, absolutely not!
Qin Ming was already hesitating. Which was more important, his lover or his career? He asked himself honestly. He didn't seem to have much affection for this woman; it was more of a habit. Women, after all, were everywhere. This was a learning opportunity…

"I am also willing to renounce my island nation citizenship and join the East! I am also willing to obey the East's arrangements!"

Keiko Waseda's words startled Qin Liang. You're really going all out!

After saying that, Waseda Keiko looked at Qin Ming with deep affection: "Da Ming, wherever you are, I will be there. Whatever country you want to be, I will be that country. I will always be with you."

At this moment, Qin Ming was also somewhat moved and ashamed of his earlier thoughts.

"Ahem, Keiko Waseda, you probably don't know, it's very difficult to obtain our citizenship. Qin Ming is my brother, he's from my Qin family, it's normal for him to acknowledge his ancestors and return to his roots, so he can obtain citizenship here. You... you probably don't have that possibility."

"This isn't acceptable?" Keiko Waseda's face darkened. "Aren't you going a bit too far?"

"However... getting a permanent residency permit is still possible. Seeing how much you and my brother love each other, I'll think of a way for you."

“Okay.” Keiko Waseda nodded happily.

Qin Liang chuckled inwardly. You'll definitely be living here permanently, in a small room with a small window, with food and drink provided. You'll live here for the rest of your life.

"Liangzi, could you... arrange a computer for me? I've been seeing everyone using computers for design lately, and I want to learn this advanced technology too."

“Yes, the server room is often used for top-secret projects. After all, Da Ming and I are outsiders, so it’s not appropriate for us to go there to use the computers,” Keiko Waseda added from the side.

"Okay, no problem." Qin Liang nodded.

"It would be even better if... we could connect to our network."

"sure, no problem!"

Qin Liang glanced at Waseda Keiko and said, "The computer I gave you is of course custom-made. Even the information you obtain through the internet is a custom-made one!"

"President Qin, we have guests." Just then, the secretary in charge of reception came in to report.

"who?"

"A guest from Factory 320 has come to discuss a project with you."

Qin Liang nodded: "Okay, I'll head over now."

Under Qin Liang's leadership, Factory 320 developed the twin-engine Q-6 project and is now one of the top military aircraft manufacturers in China. In fact, they also have other projects, such as the K-8 trainer aircraft.

In 1982, the aviation industry system requested the resumption of jet trainer development. Factory 320, having previously researched the L-29 trainer and possessing substantial financial reserves, took over the project. Now…

It must be for the engine, right?

With this in mind, Qin Liang went to the other side of the conference room and saw the guests from Factory 320 waiting there.

"Comrade Qin Liang, I heard that you have received the complete data on Garrett's TFE731 engine and are going to improve and upgrade it for them. This engine is perfect for our Q5!"

What?
Upon hearing Elder Lu's words, Qin Liang's eyes widened: "Elder Lu, what did you say?"

I originally thought that everyone came for the K8 trainer jet. After all, historically, this trainer jet used the TFE731 turbofan engine. Now that we have this engine, it is normal to use it.

Unexpectedly, it's actually a top-tier (strong five) unit?
The Q-5 was modified from the J-6, with the rear fuselage remaining unchanged. It uses the WP-6 turbojet engine, with a maximum thrust of 2.6 tons and an afterburning thrust of 3.25 tons, almost identical in performance to the original Garrett TFE1042! However, its fuel consumption and lifespan are significantly different!

The WP-6 turbojet engine has a lifespan of only 100 hours and its fuel consumption is ridiculously high. Although China now has advanced equipment, the J-6 and Q-5 fighter jets are still the mainstays of the military.
An aircraft with a lifespan of 100 hours is a huge waste. If it could be replaced with a fuel-efficient and long-lasting turbofan engine, the daily operating costs of the military would be greatly reduced!
“We’ve compared them, and the two engines are about the same size,” said Mr. Lu. “We can replace the engines by simply changing the engine mounts. In this way, neither engine will need major repairs until the Q5 is retired. They are also very fuel-efficient in daily use, and the overall lifespan cost is greatly reduced.”

At this moment, Elder Lu was in high spirits: "In comparison, the performance will be greatly improved, especially our improved version. I heard that the maximum afterburner thrust can reach 4.5 tons, and the Q-5 can fly at Mach 2 or higher! Of course, even without afterburner, it can still fly at the performance of the existing model, Mach 1.2 is a sure thing, which is supersonic cruise..."

Now that you mention it... it actually seems plausible!
The so-called supersonic cruise sounds incredible, but in reality, it simply means that the aircraft has enough power that the thrust is the same whether it uses afterburner or not!
If the maximum afterburner thrust can reach 4.5 tons, the thrust without afterburner should be around 3 tons, right?
The world's first aircraft with supersonic cruise capability was actually the Q-5?

If that's the case, then there's probably no need to install an afterburner at all, which would save weight. Attack aircraft don't need to fly that fast.

"Comrade Qin Liang, Comrade Qin Liang?"

Qin Liang then came to his senses: "Okay, as long as the Air Force has no objections, once we produce the prototype, you can modify one and try it out. However, we already have the twin-engine Q-6, so modifying it into a Q-5 might be a bit... risky..."

"No, no, President Qin, the twin-engine Q-6 is too expensive. Many customers still hope we can provide low-cost fighter jets. We can upgrade the Q-5 with advanced avionics and replace the engines. The price of the Q-5 will still be very cheap, but its combat capability will be completely transformed. It definitely has a great market prospect, especially for our brothers in Asia, Africa and Latin America..."

Qin Liang nodded: "Okay, then so you came to me just for this?"

"Of course not, there's also the engine for the J-8. This is just a small matter. Just give us the engine information, and we can match it ourselves."

In 1987, Lao Ba came to Dongfang and visited Factory 320. He took a liking to the trainer aircraft and they cooperated. They named it K8, but the name used by the Air Force in China is still JL-8.

Currently, this aircraft has not been exported yet; the domestically used model is, of course, the JL-8.

"Oh, I know."

The trainer aircraft I thought was important was actually just a minor character. The real key was replacing the engine of the Q-5. I wonder what the people on the other side of the river would think if they knew that the engine they longed for was only fit for attack aircraft on the mainland.
As for the J-6... even if the engine is replaced, it probably won't make much difference, so it's just waiting to be phased out. Only the Q-5 is still going strong.

On the other side, Qin Ming was very happy to have obtained the computer and put it into his temporary residence. He turned on the computer and immediately began to study how to work on it. Waseda Keiko was also watching attentively.

As night fell, the two sat at the dining table, eating the food they had brought back from the cafeteria.

"This computer-aided design software is so advanced! The more I use it, the better it gets. I'll look forward to the future..."

As Qin Ming spoke, he felt his eyelids begin to droop and his head spin.

"Da Ming, are you tired? Go to bed and rest."

Qin Ming had just gotten into bed and was fast asleep, while Waseda Keiko sat in front of the computer and began typing furiously on the keyboard. She first searched for other computers on the network, logged in, and then used one computer as a springboard to log into other computers, jumping back and forth. After three attempts, she finally began to access the largest server.

Inside the room, the lights were off, with only the computer screen emitting a soft glow. She had spent a great deal of effort trying to figure it out, but to no avail. Just as she was about to give up, she suddenly discovered a back door and found some information through it.

The first folder excited her.

Report on the first domestically produced advanced trainer aircraft!
She quickly copied the document to her local machine, and while copying other content, she opened the document and read its contents!
Recently, we received a project to develop an advanced trainer aircraft. We believe that we can take this opportunity to launch a domestically produced advanced trainer aircraft project...

These guys are actually using their own funds to develop their own project! But...that also shows how dedicated and serious they are about this project...

(End of this chapter)