The train driver in the courtyard

The development of the airborne ultrasonic flaw detector is progressing smoothly.

After discussing with Chief Engineer Su, Li Aiguo, based on his experience from later generations and considering the technological conditions of the time, finally determined the aviation standards.

频率覆盖2.25/2.5MHz、4/5MHz和10MHz三档，确保具备对不同材料和缺陷的检测能力。

With a resolution of 0.1mm, it can detect cracks as thin as a hair.

This standard also became one of the first navigational aids.

However, increasing the power of the probe alone is far from enough to improve the resolution. Zong Xianfeng tried several methods and conducted dozens of experiments, but he still couldn't get it right.

Li Aiguo proposed an idea: "Since the probe's power is insufficient, why don't we increase the area of ​​the transmitter and receiver, and make it into an arc shape to concentrate the sound waves?"

Upon hearing this, Chief Engineer Su's eyes lit up: "You mean to manufacture the probe in the shape of a radar?"

"No one stipulates that the probe must be a sphere, right?" Li Aiguo remembered seeing aerial flaw detection equipment on television in his later life, and he found it strange at the time, wondering why it was similar to radar. The reason is this.

“That’s true.” After pondering for a moment, Chief Engineer Su realized that he had made a mistake based on empiricism.

When it comes to building radar, Chief Engineer Su is also an expert, but this arc-shaped probe is still far from being comparable to a real radar.

After Li Aiguo drew up the blueprints, the manufacturing of the arc probe was put on the agenda.

Because it was an experimental probe, Li Aiguo and Chief Engineer Su personally took charge of its manufacturing to facilitate modifications.

Mr. Su was among the first batch of chief engineers in China to specialize in mass production of aircraft, and he has extensive experience in large-scale aircraft manufacturing.

Li Aiguo frequented online forums in his later years and gained some understanding of the aviation industry, especially the development of military aircraft. Although he lacked experience, some of his views impressed President Su.

The two worked together while chatting animatedly.

"Old Su, as an expert in manufacturing military aircraft, what do you think is our biggest hidden danger in air combat?" Li Aiguo asked while measuring the arc.

"The problem is, naturally, we have to match the war eagle with a top-notch horse," President Su sighed and replied.

Li Aiguo had also heard of this theory and asked with some curiosity, "How does the matching work?"

President Su glanced at Li Aiguo, knowing he had sufficient clearance to maintain secrecy, before speaking: "On the northern battlefield, our main fighter jet is the MiG-15, and our opponent is the American F-86, one of the most advanced jet fighters in the world."

"Over the sea, our main force consists of J-5 and J-6 fighters, while our opponents are the US's RB-57 and U-2 high-altitude reconnaissance aircraft, escorted by F-4 Phantoms."

"In order to deal with the superior horses on the other side, our pilots have to rely on their skills to fight back."

Li Aiguo nodded and said, "If you have the strength to crush your opponent, who would want to play a game of skill with them!"

This sounds somewhat incorrect.

However, it's important to understand that those acrobatic maneuvers are often accompanied by immense danger; pilots are risking their lives by hanging their heads on the wings of their fighter jets.

The most common tactic used by J-5 and J-6 fighter jets is "leap interception." How is it done?

First, it accelerates at low altitude and then sprints upward, before briefly breaking through the ceiling to approach the target.

However, this maneuver is prone to malfunctions such as engine stalling and fuel exhaustion due to extreme flight conditions.

This forced pilots to risk their lives, which was a disgrace to the technicians.

General Su continued, "In order to make up for the technological gap, our fighter jets have to be on high-intensity duty, which has increased the wear and tear on parts and the probability of failure."

"We know that matching a warplane with a top-class horse is a mistake, but what can we do? We can't build one."

Li Aiguo understood Su's feelings and added, "To make up for the technological gap, we have to deploy more fighter jets and personnel to carry out intensive patrols, which consumes resources that could have been used for industrial construction and technological research and development, resulting in a slower pace of research and development iteration and falling into a cycle of 'passive response and resource consumption'."

Upon hearing this, President Su's expression changed.

If he had only analyzed the "matching of superior horses" from the perspective of the fighter jet and the pilot himself...

Li Aiguo has already taken a strategic, holistic view.

In fact, the reason why our later development of warplanes has repeatedly lagged behind that of our opponents is largely due to this passive situation.

If only we could find a way to build a fighter jet with overwhelming superiority, like an attack helicopter that can be assembled in no time.

Li Aiguo made up his mind.

President Su stood there stunned for a long time, then sighed and said, "Yes, but what can we do? We can't make it."

"Don't worry, Lao Su, this is only temporary. We'll eventually build a truly top-notch horse and let them experience the pain of a small horse pulling a large cart." Li Aiguo finished a part, stood up, and patted President Su on the shoulder.

President Su took it as Li Aiguo joking and nodded slightly.

The development of the airborne ultrasonic flaw detector progressed rapidly, with the design work completed in just two days.

A week later, the first airborne ultrasonic flaw detector was assembled.

President Su asked Nanjing Aircraft Industry Group to send over the wings of the CJ-6 trainer aircraft for testing.

This thing uses an aluminum cantilever structure and employs flat-head rivets and stress-skinning technology.

It looks somewhat rudimentary, but it balances strength and lightweight design, and effectively reduces costs. No wonder the CJ-6 has a lifespan of several decades, so much so that it can still be seen in later generations.

Zong Xianfeng and the technicians from Nanfei completed the preparations.

President Su looked at Li Aiguo and said, "Comrade Aiguo, would you like to start it?"

"Please take it back," Li Aiguo said, offering his seat.

President Su paused for a moment, nodded to Li Aiguo, and without any hesitation, pressed the start button.

Compared to civilian flaw detectors, the startup noise of an aerial flaw detector is quite significant, with a buzzing sound coming from the fan cooling the exciter.

After the preheating was complete, General Manager Su adjusted the relevant parameters, aimed the arc-shaped probe at the wing, and pressed a switch.

Mr. Su held the probe and moved it at a steady speed, his eyes fixed on the waveform changes on the screen.

When the probe slid past the seventeenth flat-head rivet in the third row, a sharp bulge suddenly appeared in the previously stable waveform, which then quickly subsided.

"stop!"

General Manager Su said in a deep voice: "The defect has a diameter of 0.12mm and a depth of 1.3mm, and is suspected to be a microcrack."

Upon hearing this, the comrades at the Qianmen Locomotive Depot's workshop breathed a sigh of relief. After all, the wing that Nanfei had delivered was definitely defective.

But they soon realized something was wrong.

The comrades from Nanfei who were in charge of transporting the wings all had strange expressions on their faces.

Li Aiguo also noticed something was wrong and asked Zhang, the engineer in charge of transportation from the Nanfei technical team, "What's wrong?"

Engineer Zhang pointed to the wing and said, "There is indeed a defect inside the wing, but not in this location; it's in the front part of the wing."

The comrades who flew south also began to whisper among themselves.

"Is there something wrong with this machine?"

“There’s definitely a problem. This wing is custom-made, manufactured by the best workers in our factory, and has undergone four or five inspections. There’s absolutely nothing wrong with this position.”

"Perhaps the machine isn't properly set up. Everyone, please be quiet and listen to what Comrade Aiguo has to say."

All eyes immediately fell on Li Aiguo.

Li Aiguo calmly stepped forward to check the flaw detector and personally repeated the operation, but the screen still showed that there was a problem in that location.

"Is it possible that the hidden damage to this wing is more than just the one you caused?"

"impossible!"

Li Aiguo also felt that the technology from Nanfei should be fine, and breathed a sigh of relief, saying, "Perhaps there was a problem during transportation. It's easy to figure out; just open it up and check."

Li Aiguo's words seemed to be addressed to the comrades flying south, but in reality, he was asking for General Su's opinion.

"Great men taught us to seek truth from facts and to dare to question. Now that we've encountered a problem, let's solve it. Comrade Patriot, go for it, I'll assist you."

With General Su assisting him, Li Aiguo once again activated the flaw detector to inspect the wing.

This time, in addition to identifying the defects we had just discovered, we also found the defects that Engineer Zhang had laid out in advance.

"You can really tell."

"Could it be true, as Li Aiguo said, that a second defect also exists?"

"Maybe."

Even those comrades who had held firm to their opinions began to waver at this point.

Several comrades stepped forward, picked up tools, and helped Li Aiguo disassemble the wing. Li Aiguo then marked the defects he had identified beforehand.

Zong Xianfeng and the wild car expert carefully held the disassembled wing skin, picked up the chainsaw and cut it according to the marks. When the cut surface of the aluminum alloy was exposed to the light, everyone's breath suddenly stopped.

A faint, hair-thin dark line was clearly visible.

If it weren't cut open, it would be almost undetectable.

Engineer Zhang rushed forward, his face changing from initial skepticism to disbelief, and finally turning deathly pale.

"There really is a crack!"

His voice trembled slightly, "This is a critical node in the wing's load-bearing structure. If the plane takes off and encounters strong winds, the entire wing could be damaged."

These words exploded like a thunderclap in the crowd.

Comrade Nanfei, who had just questioned the flaw detector, was now completely silent.

The studio fell completely silent as everyone conjured up terrifying images in their minds.

The CJ-6 trainer was flying through the clouds when its wing suddenly broke off. The fuselage lost its balance, tumbled, and plummeted. The screams inside the cabin were swallowed by the airflow...

Thinking about this, many people's backs were soaked with cold sweat.

Engineer Zhang was also stunned by the terrible consequences.

"Thanks to Comrade Aiguo! If this wing had actually been installed on the plane, not only would our reputation as a South Aircraft Corporation have been ruined, but we would also have been burdened with the debt of countless lives! We were stubborn before, and we wrongly blamed your equipment and your professionalism!"

"You're too kind. We're all doing this for the safety of the warplanes. There's no right or wrong here," Li Aiguo quickly waved his hand.

He didn't mean to blame Engineer Zhang.

Even in later generations, aviation accidents caused by problems with spare parts still occur frequently.

All people can do is try to avoid it.

"Now that we have this flaw detector, we can check all the materials when we get back." President Su was very happy, as it was better to find problems on the ground than in the air.

Subsequently, General Manager Su reported the test results to the ministry and wrote down the inspection process in the report without any concealment.

After a brief discussion, the ministry leaders approved General Manager Su's retesting plan and ordered him to immediately take the equipment back to Nanfei.

The ministry also decided to revise the maintenance plan for fighter jets, requiring them to be inspected with flaw detectors after each mission and upon returning to base.

Although it is time-consuming and laborious, it can ensure the safety of fighter jets and pilots.

The aviation department placed an order for twenty airborne flaw detectors with the Xiangmen Maintenance Depot. Once manufactured, they will be distributed to various aircraft factories and aviation bases.

After receiving the order from the aviation department, Section Chief Xing of the Qianmen Locomotive Depot scratched his head: "Li Aiguo actually managed to build this thing?!" This time, he wasn't annoyed by the large number of orders the Qianmen Locomotive Depot had.

Even if you have to do it yourself, you still have to complete the delivery on time.

Originally, a celebration banquet was planned after the test was successful, but now it has to be canceled.

In the afternoon, Li Aiguo saw General Su and the comrades from Nanfei off onto the train. General Su waved to Li Aiguo and said, "Comrade Aiguo, we really have to thank you this time. Nanfei welcomes you to visit us anytime."

"Haha, then you'd better prepare some food and drinks. By the way, I don't have many hobbies, but I love eating tiger meat the most," Li Aiguo replied half-jokingly, waving goodbye to his comrades.

Li Aiguo returned to the Qianmen Locomotive Depot in the evening. The batteries from the Torch Factory had already been delivered, and Zong Xianfeng and his team were modifying them, which would take a few more days.

Tomorrow is the weekend, and Li Aiguo plans to take a day off.

The weather is getting hotter and hotter, so the Qianmen Locomotive Depot distributed electric fans to the employees who made contributions, and Li Aiguo received one.

There's already a fan in the bedroom, so this one will fit perfectly in the study to save us the trouble of moving it back and forth.

As soon as I plugged in the power cord to test it, I heard He Yushui cheering outside.

"Brother Aiguo, sister-in-law, the results are out. I got 410 points."

Li Aiguo pushed open the door and went out, only to see He Yushui as excited as a child who had just eaten a White Rabbit candy.

No wonder she was so happy. In those days, the high school entrance exam used a four-subject format: Chinese (120), Mathematics (120), Politics (100), and Physics and Chemistry (100), for a total score of 440.

A score of 410 is already among the top, allowing you to choose any excellent high school.

Li Aiguo was also happy for He Yushui. This girl was very smart, but she was held back by Sha Zhu. If she went to university, her future would be even brighter.

In particular, He Yushui has some mathematical talent, and even Chen Ziliao thinks she can continue to study mathematics in the future.

Not many students could catch Chen's eye.

"Brother Aiguo, you promised me you'd take me to ride the duck boat tomorrow," He Yushui said, pulling on Li Aiguo's arm.

Chen Xueru came out of the house, beaming, "Don't worry, your brother Aiguo doesn't have to work tomorrow, so he'll definitely take you."

He Yushui then happily skipped away from the house.

The news that He Yushui scored 410 points in the college entrance examination quickly spread throughout the compound.

This made many residents somewhat envious.

"I hope my child can rank among the top in the city in the future."

"It's just that Yushui is lucky. She met Li Aiguo and was taken in as a daughter by Aunt Liu. If Shazhu were still here, she might be in vocational school by now."

"Yes, with such good grades, you'll definitely be able to go to university in the future."

"I want to go to university too." Hearing the voice, the residents looked up and saw Banggeng squatting on the ground poking at ant holes with a stick.

The residents all shook their heads.

Banggeng is a troublemaker all day long, and the residents are having a lot of headaches.

However, Qin Huairu was pregnant and couldn't manage Banggeng. The residents were even less willing to argue with a child, and Banggeng had now become a nuisance in the compound.

"Don't worry, the old man is going to have a meeting tonight to discuss this issue," the well-informed old woman said.

Upon hearing this, the residents became even more anxious.

What can Yi Zhonghai do? He can't just send the baton away, can he?
Because He Yushui achieved good results, Aunt Liu specially bought some meat and tofu and cooked a sumptuous dinner that evening.

Li Aiguo and Chen Xueru brought their three children to Aunt Liu's house for a meal.

The dinner table was lively, and Xiao Hongsheng even raised his little hand and said, "I want to learn from Aunt Yushui in the future."

This remark elicited a burst of laughter.

As dinner ended, the sound of the Third Uncle breaking a gong could be heard outside.

Li Aiguo had already learned about the meeting from Aunt Liu, so he strolled towards the central courtyard.

When they arrived at the Intermediate Court, all the residents of the compound had already gathered, including Liu Haizhong, Uncle San, Yan Jiecheng, and Xu Damao.

Seeing that everyone had arrived, Yi Zhonghai, unusually, didn't waste any words and went straight to the point: "Today's meeting is to discuss the Jia family's affairs. Huai Ru is heavily pregnant and needs to take care of herself, so it's difficult for her to take care of both children, especially Bang Geng."

Furthermore, Huai Ru will have to go back to work after giving birth, so she'll have even less time to take care of Bang Geng. What are your thoughts on this?

As soon as he finished speaking, Xu Damao, as usual, sang a different tune.

"Uncle, I heard that Auntie agreed to take care of Qin Huairu. Why don't you take care of Banggeng as well? Banggeng is your grand-disciple, after all."

This statement immediately garnered the approval of the residents.

"Yes, the old man has no children, so Banggeng might take care of him in his old age and see him off when he grows up."

"Even if Jia Dongxu is underground, he will be at peace."

"This old man is a moral exemplar in our compound. Surely he wouldn't refuse to help with something so small?"

Yi Zhonghai was practically cursing Xu Damao to the core in his mind.

If he wanted to take care of Bang Geng, would he need to hold a meeting?

"Ahem, as you all probably know, my health has never been good. The children are too noisy. Besides, my husband is already struggling to take care of Qin Huairu."

"Everyone should look at other families, see if they can take care of the pigeons, preferably families with fewer children."

Upon hearing this, the residents finally understood Yi Zhonghai's intention: he was trying to push away a hot potato.

The group exchanged glances but no one responded to Yi Zhonghai's words; none of them wanted to bring the sticky rice cake into their homes.

At that moment, a voice rang out.

"My second uncle's family has successfully raised three children; they are all sensible children. Why don't you help take care of some of the kids?"

Everyone looked in the direction of the voice and saw that it was Li Aiguo speaking.

Liu Haizhong originally didn't intend to get involved in this matter, after all, he has three children.

But upon closer examination, Liu Guangqi went to a third-tier factory, and Liu Guangtian and Liu Guangfu were both grown up, so it wasn't as easy to discipline them.

If we take Banggeng back, he can continue the great cause of education and outshine the Third Uncle in the compound.

But there's still a problem.
Liu Haizhong raised his head and said, "I am the second oldest in the compound, so I don't mind helping out. However, as everyone knows, my family's parenting style is quite unique, and I'm worried that Qin Huairu might have objections."

Everyone then turned their attention to Qin Huairu.

Qin Huairu was also troubled by the sticky stem.

Jia Zhangshi led Banggeng astray, causing him a lot of trouble. No mother wants to see her child go astray.

Qin Huairu hesitated for a moment, bit her lip and stamped her foot: "Second Uncle, I'm entrusting Banggeng to you from now on. Don't worry, I will definitely not stop you from disciplining him."

Bang Geng didn't take this to heart. No matter whose house he went to, who could stop him?
Now, however, I'm starting to get anxious.

"Mother, no! I don't want to leave you!"

Liu Haizhong strode up, ruffled Bang Geng's hair, and chuckled, "Bang Geng, from now on you'll be with Guang Tian and Guang Fu. I promise to treat you like my own son."

"Huh?!" Bang Geng's face turned pale and he almost fainted on the ground.

After the meeting, Liu Haizhong led Banggeng home.

When Liu Guangtian learned that Banggeng would be under the Liu family's tutelage, he immediately perked up, got off the bed barefoot, and pulled down Banggeng's pants.

"Father, hurry up and hit him!" Liu Guangtian handed the leather belt with the brass buckle to Liu Haizhong.

In the days that followed, the third uncle stopped being proud of his status as a former teacher and began to praise Liu Haizhong for his effective teaching methods.

Yi Zhonghai was eager for someone to take over, and he even gave Liu Haizhong a thumbs up, which was quite rare for him.

The residents in the compound breathed a sigh of relief when they saw that someone was taking care of the rice stalks.

Qin Huairu hopes that Banggeng can get back on the right track under Liu Haizhong's guidance.

Aunt Liu praised Li Aiguo's method as particularly good.

Xu Damao, however, felt that Li Aiguo was trying to rid the courtyard of pests.

Everyone won.

On Monday, Li Aiguo led the locomotive depot to work as usual.

With the batteries delivered by Torch Factory, the mass production of railway-specific ultrasonic flaw detectors has been put on the agenda.

Li Aiguo specifically studied that battery, which was considered cutting-edge technology by today's standards, with an energy density that was in no way inferior to similar products from abroad.

If we develop new energy electric vehicles in the future, we can consider cooperating with Torch Factory.

This is also why Li Aiguo wants to do so many things outside his field; only by building relationships in all aspects can he make the most of resources.

The mass production of the railway-specific ultrasonic flaw detector went smoothly, and the first batch was shipped out of the workshop two days later.

It looks rather rudimentary: an iron box, an iron rod, and a wooden box containing the oscilloscope.

However, the results were quite good. Li Aiguo experimented on the abandoned railway tracks several times and was able to accurately find the hidden damage inside the tracks each time.

"Send this batch to the line workshop first."

Zong Xianfeng was in charge of delivering the goods, and at the same time, he could teach the track inspectors how to use them.

After finishing these tasks, Li Aiguo turned and walked towards the studio, intending to continue helping Professor Qi to get the armed helicopter out as soon as possible.

Before he even entered the door, he received a notification from Section Chief Xing.

"Patriot, that bearded Middle Eastern guy is here. He says he wants to pick up his car."

"Big Beard? Sadam?"

Li Aiguo was also stunned by the news.

That custom-built SUV has been stored in the workshop for more than half a year, and there has been no movement from Sadamu's side.

Why are you here now?
Could it be that something has changed in Xiao Yi's family? Did Saddam fail and come here to seek refuge?

However, Li Aiguo quickly rejected this idea himself.

The fact that Sadam could come over openly and honestly shows that his own safety is not a problem.

Why is that?

Regardless, preparations should still be made.

Li Aiguo went into his office, made a phone call to the weather station, reported the situation, and then asked the Wild Car Experts to perform maintenance on the custom-made SUV.

(End of this chapter)