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

Chapter 509 Night skating went smoothly, and now we want to discuss the next generation?
The Su-27 can perform the same maneuvers as the Su-27, such as the falling leaf maneuver, and it also has features that the Su-27 lacks, such as stealth!
After all, our aircraft is a generation ahead of the Su-27!
Listening to everyone's introductions, Qin Liang was filled with emotion.

"Of course, the current engine's thrust is not very strong. The 606 Research Institute in China is already developing a new turbofan engine, codenamed WS-15. This engine is aiming for a higher starting point, targeting the American YF-120 engine..."

and many more!

Upon hearing what Elder Song said, Qin Liang's eyes widened: "Comparable to the YF-120?"

"Yes, the variable cycle engine has top-notch performance in all aspects. Principal Qin, do you... have any objections?"

Even if we're going to compare it to something, shouldn't we compare it to the YF-119 engine?

The engine project was launched in 1982 and made its maiden flight with the F-22 in 1997.

This is the world's first engine with a thrust-to-weight ratio of 10.

Although there were many rumors in later generations that the engine's data was falsified, Old Ma's team launched an investigation and concluded that its thrust-to-weight ratio was only 7.

However... the thrust-to-weight ratio is related to many factors, such as its weight (dry weight, wet weight), and whether it has a nozzle or a vectoring nozzle.

These factors can cause significant differences in the weight of the engine itself. For example, the RAND Corporation's data shows a dry weight of 3900 pounds, or 1769 kilograms. However, later documents that accused the company of falsifying the data raised the dry weight to 5000 pounds, based on data obtained from the packaging and transportation of the engine.

Of course, the Americans did indeed falsify data. In early tests, the engine's thrust was over 170 kN, but when it went into mass production, the thrust was finally set at 156 kN. This reduction was probably for the sake of lifespan.

Despite its flaws, the F119 engine's excellence cannot be overstated, even if it is a forgery. Many of its performance characteristics are undoubtedly world-class.

Now, instead of comparing ourselves to the F-119, are we comparing ourselves to the YF-120?

"This YF-120..."

"The YF-23's engine—currently, this aircraft has the highest demand and the fastest project progress..."

Qin Liang then realized that he had fallen back into his original timeline due to habitual thinking! In this timeline, Lockheed's project was ruined, and Northrop's YF-23 became the most popular aircraft. This aircraft was planned to be equipped with the YF-120 engine, which is the famous variable cycle engine!
At low speeds, it is a turbofan with a high bypass ratio, and at high speeds, it is a turbofan with a low bypass ratio, similar to a turbojet. The design concept of this engine is very ingenious, enabling the YF-23 to achieve supersonic cruise capability of Mach 1.8.

High-pressure rotor fan and variable-pitch turbine guide vanes are features not found in other aero engines. The variable-section bypass ejector gives it powerful thrust under different operating conditions. It can be said that this is a revolutionary engine!

Unfortunately, with the cancellation of the YF-23 project, this engine project was also cancelled.

In reality, even research and development can fail to be completed due to various defects.

As for now...

"General Electric decided to cooperate with Northwestern Polytechnical University to speed up the research and development process. It just so happens that we can also absorb the development ideas of this engine." Yang Wei added from the side, "So, Institute 606 has locked onto this direction."

Previously, we had collaborated with General Electric on fan blades!
Now, General Electric has secured the supporting work for the YF-23, which is a huge challenge for them. They know how difficult it is to develop this engine, so they hope to collaborate with Dongfang. As a result, we can obtain the corresponding technology and improve our R&D capabilities based on this technology.

Qin Liang took a deep breath: "Alright, since they've all chosen this direction, let's hope they can successfully complete this research and development task."

Northwestern Polytechnical University deserves support!

The WS-10 turbofan engine has been a success, so the WS-15 needs to bring about revolutionary changes!

In later generations, the WS-10 began to dominate the market, while the WS-15 was scrapped several times because its performance was inferior to the modified WS-10, so there was no need to use it. It is even said that the sixth-generation fighter jets were equipped with the WS-10.

If the WS-15 turbofan engine is to be developed, then performance indicators must be improved, and variable cycle technology may indeed be a viable approach.

Even if the Americans didn't succeed in developing it, it doesn't mean we can't!

After all, we've already accomplished the task of learning by analogy! Now, it's time for us to innovate!

"This prototype doesn't have all the avionics installed, does it?" Qin Liang asked again.

Generally speaking, the first prototype is used to test the aerodynamic characteristics of the fighter jet; radar and other components can be replaced with counterweights.

The second prototype will never take to the skies; it will require static testing.

The third prototype will be the complete version.

Hearing Qin Liang's words, Yang Wei smiled and said, "Senior, you're in the new campus, so you don't know about the progress of our old campus. The Department of Electronic Engineering is developing very fast. They have already completed the research and development of airborne phased array radar. We've already installed one in the nose of our aircraft, and its performance is several times better than before!"

Shipborne phased array radar has been developed, and airborne radar should not lag behind. Even if one is S-band and the other is X-band, many of the principles are the same!

As Yang Wei explained, an engineer had already opened the nose radar dome. Since a pre-flight inspection was necessary anyway, it wouldn't hurt to do it again, even if it had already been checked.

"Because the nose section has enough space, our radar has 2200 T/R modules. The maximum transmit power of a single gallium nitride module is 20 watts, so the maximum transmit power of the entire radar can reach 44 kilowatts."

For fighter jets, this power is not much at all. For example, the Tornado-A radar used on the MiG-25 has a peak power of up to 600 kilowatts, and the APQ-120 on the F-4 fighter jet has a maximum power of 100 kilowatts.

However, for these early radars, high power was meaningless because the power conversion rate of radar antennas was very low!

Take the MiG-25 for example; despite its high power, its maximum search range cannot exceed 100 kilometers.

Looking at the Tomcat's AWG-9, it was the first to use a planar slotted radar antenna with a power of only 10.2 kilowatts, yet it could achieve a maximum search range of 300 kilometers. For targets the size of a fighter jet, the search range could exceed 100 kilometers.

Looking at the APG-71 radar, an upgraded version of the AWG-9, its power has been reduced to 5 kilowatts, but its performance is stronger than that of the AWG-9!

The radar used on our J-20 fighter jets is even more advanced! It's the world's first active phased array radar using gallium nitride components!

"This radar has already been tested on the Y-7 transport aircraft." Old Song introduced from the side: "It can detect a target of one square meter at a range of 260 kilometers, a target of five square meters at a range of 400 kilometers, and even a target with a reflective area of ​​0.01 square meters can be detected at a distance of about 80 kilometers."

To detect a stealth aircraft, you need an active phased array radar that can focus the beam on a single point to obtain the strongest reflected wave!
Even so, the distance still needs to be shortened to eighty kilometers!
However, in this day and age, eighty kilometers is already quite impressive!

Even the most advanced American AIM-120 missile doesn't have such a long effective range, which means that our side can detect and lock onto targets completely outside the enemy's range.

Moreover, the Americans' YF-23 might not even be able to detect our side at this distance!

After all, they use gallium arsenide components, and the power of a single T/R component will not exceed 10 kilowatts. The power of the entire radar is less than half of ours, and it would be good if the search range could reach 70% of ours!

In that case, if the enemy can detect us at a distance of fifty kilometers, they are incredibly lucky. At that distance, our missiles would have already been fired!
This is the advantage brought by advanced technology!

After catching up with the third-generation fighter jets, we have now completely surpassed our opponents in the fourth-generation fighter jets!

"In addition to radar, we have also prepared optoelectronic methods to detect targets," Yang Wei continued.

Electro-optical devices are not a Russian invention. The devices on the MiG-29 and Su-27 are indeed very famous. In fact, the American Tomcat fighter jet was equipped with electro-optical sensors!

The Russians' optoelectronic devices were modified because they knew their electronics technology was inadequate and couldn't function properly under strong electromagnetic interference. Ours, on the other hand, were designed to allow us to secretly track target aircraft while radar remained silent.

After all, once the airborne radar is turned on, there will be electromagnetic signals, and the enemy will be able to detect it, while optoelectronic devices are completely passive.

In this way, under the command of the rear early warning aircraft, our own aircraft can approach the target silently and then take out the opponent!
Stealth aircraft are best suited for stealthy attacks, striking once and then immediately fleeing, without ever engaging in hand-to-hand combat with the target!
"Hmm, not bad, not bad!" Qin Liang nodded in satisfaction.

The master leads you through the door, but the practice is up to you!
Northwestern Polytechnical University used to need to lead itself to progress, but now... that's no longer necessary! Everyone can leverage their abilities to drive advancements in various technologies!

"Alright, it's about time. We can tow the plane out now!"

Only when they heard Old Tu's voice did everyone realize: it was dark outside!
Yes, it's dark!

To further enhance secrecy, all J-20 test flights must be conducted at night!
With the support of advanced technology, there is little difference between night and day; everything can be seen clearly through night vision goggles. For reconnaissance satellites, the reconnaissance effect at night is almost negligible.

Back then, the Americans tested their F-117 under these conditions, and subsequent training was also conducted at night. Now, we're just trying to keep it as secret as possible. If it does leak one day, we'll just openly reveal it and let the whole world see.

After all, we design new aircraft for so many countries, so our own technology must be number one in the world!

Even the Americans need our help!

The workshop door opened, and this brand-new aircraft left the factory for the first time, stepping outside!
This is its true domain!

Tarmac.

Lei Qiang, carrying his flight suit, strode over.

"Lei Zi, are you confident about this experiment?"

"Yes, a gliding test? That's not going to stump us!"

It's impossible for it to fly into the sky right after it leaves the factory; the first thing to do is a taxiing test.

Low-speed gliding tests agility; medium-speed gliding checks for deviation; high-speed gliding assesses lift...

“Our runway has been extended by several hundred meters, and the J-20 has better aerodynamic characteristics, so all taxiing and running maneuvers can be conducted here,” Old Tu said from the side.

When the J-9 made its maiden flight, it encountered this obstacle, which was finally resolved when Lei Zi's hand trembled.

These are not problems at all for fourth-generation fighters. According to the design specifications, they can lift their noses up in just over 200 meters! That's how powerful their performance is!
Hearing what Elder Tu said, Qin Liang was filled with emotion.

The second brand-new fighter jet has begun its test flights!
Lei Qiang stepped into the cabin, and a few minutes later, the roar of the engines began, with the two engines starting up one after the other.

A new aircraft with a new engine – this is almost the first time!
The reason it can be used this way is because the engine was developed earlier than the aircraft; otherwise, it simply couldn't keep up!
At this point, after starting, Lei Qiang released the brakes, and the fighter jet began to slide on the tarmac, heading towards the runway. It easily passed through several curves one after another.

Low-speed gliding end!
Next comes the medium-speed skating!
With the throttle fully open and afterburner not engaged, Lei Qiang released the brakes, and the fighter jet began to taxi on the runway.

The speed is getting faster and faster!

Thirty, fifty, one hundred, one hundred and fifty...

The plane was very stable, with no signs of veering off course!
Medium-speed skating, all successful in turn!

Lei Qiang turned around ahead, skidded back, did another medium-speed skid, and then... made a call on the radio.

"Lei Zi is calling, requesting to conduct a high-speed gliding test."

In one night, all the gliding experiments were done. This was definitely a first for a young woman!
Old Song didn't mince words: "Sure! I'll take responsibility if anything goes wrong!"

Mr. Song has always been a person who can take responsibility!

Moreover, this is in line with the laws of scientific research. After all, if there is no problem with medium-speed skating, then of course we should continue to work hard!
If the high-speed taxiing goes smoothly, then after processing the taxiing data in a few days, we can have our maiden flight!

"Yes!"

Lei Qiang was also very excited. He realigned the track and this time activated afterburner.

Amidst the roar of the engines, the fighter jet began to accelerate again.

One hundred, two hundred!

The skating distance was less than 200 meters, but the speed had already exceeded 200 kilometers per hour!
Lei Qiang gently pulled the control stick, the canard in front deflected, and the nose of the aircraft was successfully pried up!

The high-speed taxiing was successful in sequence, demonstrating excellent takeoff characteristics!

"That's the advantage of a lift coefficient of 2.0!" Qin Liang couldn't help but exclaim.

The F-22's data fabrication involves many aspects, and lift coefficient is one of them. The Americans advertised it as 2.0, so we made various efforts to research and try to achieve the same lift coefficient. With a conventional layout, we could never achieve it; we had to add canards.

How did the Americans achieve that?
We had our doubts, but we waited until later, when the data was declassified, to find out that the F-22's lift coefficient was only 1.7!

The Americans are responsible for the boasting, we're responsible for the execution.

Now, we're not chasing after the Americans anymore; our data is already unmatched by them!

“That’s right, our aircraft aerodynamic design is absolutely the best. Now, we’ve caught up in engine technology as well, and we have almost no weaknesses.” Old Song nodded: “President Qin, we really have to thank Northwestern Polytechnical University for this.”

"Ahem, it's nothing. Northwestern Polytechnical University is all about aerospace, aviation, and marine engineering."

"Principal Qin, once this aircraft completes its test flight, what... what should we do with our next aircraft?"

Qin Liang then realized that Old Song's most important goal was to raise this question!
Back when they were working on the J-9 fighter jet, Mr. Song was incredibly excited, thinking that working on just this one model for his entire life would be enough!

After the success of the J-9, he started working on a stealth aircraft, keeping himself extremely busy every day. And now, with the stealth version of the J-20 about to make its maiden flight, Mr. Song is already planning the next aircraft!

"Yes, now all countries are using stealth aircraft. Although we've already stood out with the J-20 and become the top fourth-generation fighter, other countries will soon catch up. We still need an even more advanced aircraft," Tu Lao added. "We in Chengdu need to leverage our strengths and continue to lead the world..."

Factory 132 was willing to merge with Factory 611, and one important goal was to develop a brand new aircraft!
We want to lead the world!

How to stay ahead?

Of course, it's the next generation of aircraft!
Fourth-generation fighters pursue 4S (Superior Performance, Superior Stability, Super ...

Both Mr. Song and Mr. Tu are very much looking forward to it, hoping to send the most advanced aircraft into the sky in their lifetime!
At this moment, the J-20 had already begun to decelerate, the nose landing gear dropped, and the fighter jet came to a stop. It used less than 500 meters of runway length in total. This maneuver was absolutely graceful!
Glide back to the end of the track, and tonight's gliding test will be successfully completed.

"Let's go to the cafeteria, there's a celebration banquet!"

There's a celebration banquet only for the maiden flight. We've just finished taxiing, why would we need a celebration banquet?

Qin Liang naturally knew that this was not a victory celebration banquet, but a ploy to get him drunk and to present the design plan for the next aircraft.

My brain is probably going to be completely emptied out.

canteen.

"Come on, let's raise a glass together to celebrate the successful completion of tonight's skating experiment!"

"Come on, let's all raise a glass to President Qin! Without Northwestern Polytechnical University, there would be no J-20 fighter jet!"

"On behalf of the engine team, I would like to raise a glass to Principal Qin!"

"On behalf of the avionics team..."

"Okay, okay, I can't drink anymore."

Qin Liang looked at the people raising their glasses and waved his hand helplessly: "You all want to hear about the next project, right? Well, I'll tell you about it. It will definitely use a lot of groundbreaking technologies, for example..."

"An engine? Principal Qin, our engine department's knock engine is progressing smoothly! It will definitely be ready for installation within five years, and its theoretical maximum speed can reach Mach 9!"

What? Qin Liang was shocked again.

(End of this chapter)