In fact, Song Zhewu is not very urgent about tanks now, because in the Anti-Japanese War, at least in the early stage of the Anti-Japanese War, he almost did not need a tank as a weapon.

In World War II, the world's great powers paid the least attention to tanks, and the basis of the research and development of tank technology was the French "Renault" FT-17 light tank and the British "Victor" light tank, both of which were introduced in the early 20s of the 20th century.

In the early and middle years of World War II, the main tank model was the Type 95 light tank, the "famous" bean fighting vehicle, with a measly 17mm front armor. In addition, there are Type 95 "North Manchurian" light tanks, Type 97, Type ** "Qiha" tanks.

In the Pacific Theater, the number of Type III tanks and Type III modifications was about 500, and the number of Type IV tanks was only 18. The final V-tank had only one prototype, and it was defeated and surrendered before it was put into actual combat.

It is said that the Type 97 medium tank, which is the most equipped, has a total combat weight of only 15 tons, is light, has thin armor, and weak firepower, and basically does not have the ability to fight tanks. However, because in the early and middle stages of the war, Yueben mainly fought in Chinese mainland and Southeast Asia, and the combat targets basically did not have tank troops or troops equipped with only a small number of tanks, and the anti-tank firepower was also weak, which allowed Yueben's small tanks to show off their might. But on the other hand, it also inhibited the development of the tank.

If Song Zhewu can have a tank like the one he put forward for the technical data, even if it slightly exceeds his requirements, the number is not very large, and he can also win a certain advantage in the local battlefield. It's just that he knows that it is not easy to manufacture and develop high-level tanks, at least high-density alloy steel is not something he can get in large quantities in a few years.

However, he still hopes that Guo Wenyuan can make efforts in the design and manufacture of tanks, although his demand for tanks during the Anti-Japanese War is not very urgent, but in the future, it will ......

Song Zhewu stopped his thoughts, some things should be talked about then, the first thing he has to consider now is the needs of the Anti-Japanese War.

For Song Zhewu's unexpected performance in science and technology, Xiao Guodong is already a little used to it, looking at his watch, he is very afraid that Song Zhewu and Guo Wenyuan will talk about technical issues again and delay time, and said with a smile: "Wenyuan, for you not going home for the New Year, the commander is very grateful to you, today is the Chinese New Year's Eve, the commander invited you to dinner at noon, and brought these dozen students you left in the source." The commander also has to go to the airport to personally invite Ba Yuzao, Li Minghua and others, so as not to interfere with your work. ”

When Guo Wenyuan heard that Song Zhewu personally came to invite himself and the students to dinner, he was very excited, looked at the tank on the ground and said: "Commander, on the day of the Chinese New Year's Eve, we northerners have two meals during the day, and this meal in the afternoon is generally at two or three o'clock, and this tank can be surveyed and mapped in a few hours. ”

Song Zhewu personally invited these experts and scholars, the purpose was to want these people to be loyal to his Fourth Route Army and work hard, and Guo Wenyuan's enthusiasm for work was naturally not good, so he said with a deep sigh: "Okay, then set the time at two o'clock in the afternoon." ”

He said to Ye Changgui again: "Send someone back to inform you that the banquet will be changed to two o'clock in the afternoon." ”

When Song Zhewu arrived at the airport, he was catching up with a two-seater biplane with a silver paint that he had never seen and an improved French-made Spad S13 fighter, and they landed on the runway very smoothly one after the other.

If it was a newly bought plane, it was impossible for Song Zhewu not to know, could it be that Ba Yuzao and Wang Zhu, these "crazy elements", actually developed a new plane in a few months?

The behavior of Wu Jin, Ba Yuzao, Wang Xiaofeng and others, who were cheering beside the runway, proved that Song Zhewu's guess was right.

The arrival of Song Zhewu made the joyful atmosphere even higher, and Wu Jin said excitedly: "This is an aircraft designed by ourselves, designed and manufactured by President Ba, and today is the first test flight." ”

"This is an aircraft of our own design and manufacture?" Xiao Guodong didn't believe his eyes.

"Yes, Chief of Staff, this is an aircraft of our own design and manufacture." Wu Jin realized something, hurriedly closed his mouth, and looked at Ba Yuzao embarrassedly.

If Xiao Guodong, the chief manager, doesn't know about designing and manufacturing airplanes, it is indeed something that is not done properly. Seeing that Wu Jin was a little embarrassed, Ba Yuzao hurriedly explained: "The design of this aircraft was designed by me and Xiaofeng when we were in Mawei. After the establishment of the Aviation Research Institute, Commander Wu handed over to us the Soviet aircraft maintenance and manufacturing equipment and materials that the commander had captured in Manchuria, and I found 15 French-made Isoza V liquid-cooled engines in these materials and equipment. ”

Although the liquid-cooled engine has been cooled after the current air-cooled engine, the surname of this engine is still very good, its power has reached 130~220kwww.xstxt.org/h, and the ceiling is 6650m. Because the liquid-cooled engine is heavier, the aircraft we develop in the future must also use air-cooled engines if they want to reach the advanced level of foreign countries. But in this way, these dozen liquid-cooled engines are completely useless. Yu Peng and Xiaofeng and I made a calculation, and decided to use this type of engine to build the aircraft we designed first, so that these engines can come in handy, and second, it can also allow the workers of our aircraft factory to accumulate some experience in making aircraft. Therefore, I wanted to wait for the plane to test flight and then report to the chief of staff, and Commander Wu only learned about it recently. ”

Song Zhewu did not agree with Ba Yuzao's explanation, he believed that the aircraft developed like this belonged to the extensive method of herding sheep, and the random surname was too large, which could not effectively maximize the ability of these top experts and scholars, and was not conducive to the rapid development of his aircraft design and manufacturing technology, and could even be said to be a waste of Ba Yuzao, the world's best aircraft design and manufacturing talents. To change this, you need to make a plan for them, and let them run closely after the plan.

However, Song Zhewu did not express displeasure on his face, after all, this was his first aircraft with "independent intellectual property rights", and he was still very happy in his heart.

"How was the test flight?" Song Zhewu wanted to know the design effect of this aircraft, and anxiously asked test pilot Lin Anshun.

"Excellent! Very good! It is flexible, climbs fast, has a high ceiling, a small turning radius, a stable flight, and is especially good at hovering at low altitudes. Lin Anshun reported a large list of advantages of the aircraft.

"Judging from the data of the test flight just now, the maximum level flight speed is more than 230km/h, which is the best and fastest aircraft I have ever flown in." Lin Anshun said excitedly.

Gao Zhihang next to him also said excitedly: "It is indeed a very good aircraft, much better than the Sparder S13 I flew in terms of climb and turning radius, not only the ceiling is more than 600 meters higher than Spard, but the speed is also a lot faster, it can be used as a fighter, but unfortunately this is a reconnaissance aircraft." ”

In response to Song Zhewu's puzzled gaze, Ba Yuzao explained: "When we were in Mawei, the Ministry of National Defense purchased planes from abroad, and no one believed that we could also manufacture planes that were not inferior to foreign ones. And since I went to the Berlin Air Show, the prototype of the horsetail was not built, and we do not have a wind tunnel yet, so it is impossible to come up with experimental data, so we have to build a prototype to get the data. When I went to Berlin this time, I learned a lot of advanced experience from my foreign counterparts, and I came back and made some improvements. ”

"Let's take a look at the plane." Without waiting for Ba Yuzao to finish speaking, Song Zhewu impatiently walked towards the plane on the runway.

This reconnaissance plane is a biplane with a slender fuselage, and the biggest difference from previous planes is that there is no cloth skin on the fuselage of the entire aircraft, and even there are very few cables, only steel cable braces between the wings. There is also the fact that the entire fuselage is made of a wooden monocoque, rather than a truss as you can see in other aircraft. Completely a modern style aircraft.

Song Zhewu not only secretly admired Ba Yuzao, but he also wanted to find an opportunity to "give advice" to Ba Yuzao, which saved him from bothering to make up reasons.

Song Zhewu climbed up the gangway, he wanted to see the situation in the cockpit with his own eyes.

Although the fuselage of this reconnaissance plane is slender, because it does not need the functions of bombers and fighters, and there are fewer operating mechanisms in the engine room, there is a lot of space in the front and rear cabins, and there is only one transmitter and a pair of headphones and a microphone fixed to the front bulkhead in the rear cockpit.

Song Zhewu patted the fuselage with his hand and made a sound of "Peng Peng", giving people a sense of solidity. Song Zhewu was very satisfied and wanted to go down the escalator.

But suddenly he felt as if something had been ignored by him, his eyes searched in the cabin, and finally fell on the headphones and microphones in the rear cabin, and then saw that the front cabin also had the same headphones and microphones, and followed the wires connected to the headphones, and found an iron box with knobs embedded in the bulkhead under the dashboard, Song Zhewu couldn't help but feel a burst of ecstasy in his heart, and hurriedly went down the ladder to the ground.

"What are the electronic devices in the cabin?" As soon as he came, Song Zhewu asked Ba Yuzao.

Ba Yuzao smiled and said, "Commander, you should still ask Director Li." As he spoke, he pointed in the direction of the tower.

Li Minghua and Cui Hao came to the plane at a trot all the way, ignoring greeting Song Zhewu, Xiao Guodong, and Ye Changgui, and anxiously asked Gao Zhihang and Lin Anshun: "Our voice is very clear, how effective are you talking to each other in the air?" What is the maximum talk distance? ”

Gao Zhihang replied with a smile: "Our call is also very clear, and the maximum distance should be 5,000 meters." Then he said: "With this good thing, it will be much more convenient for me to command the formation in the air." ”

Li Minghua breathed a sigh of joy with joy, and then said to Song Zhewu: "Commander, the task you gave me is basically completed, and the wireless voice communication device we developed, in addition to the slightly shorter distance, the ground and air communication distance is only less than 20 kilometers, and the effect is not bad, and it should be improved again." In addition, the wireless positioning has also been done well, and through the 15-second signal transmitted by the reconnaissance plane, I can determine its approximate position and direction of movement on the ground. ”

These two devices were handed over by Song Zhewu to Li Minghua Electronics Institute, and with these two treasures, the communication problem between the ground and the air has basically changed, and even theoretically the plane has the ability to fly at night, so there is no need to worry about getting lost and not finding the airport.

After encouraging Li Minghua and Cui Hao, the happy Song Zhewu still couldn't let go of the plane, and asked Ba Yuzao: "Yunhua, why don't you use the previous truss structure for this plane, but all of them are hard-shell fuselages?" ”

Ba Yuzao said with some emotion: "I was very touched by this trip to Berlin!" In the past few years since we returned to China, foreign aviation technology has developed rapidly, and in the early twenties, although there was already a semi-monocoque aircraft structure with a shell and a partition frame or reinforcing strip that could share the load, it was not very mature. And this time at the Berlin Air Show has appeared a large number of aerodynamic surname of the full hard shell is the fuselage of the aircraft, and even appeared all metal shell aircraft, although in addition to the German civil aircraft F-13 using the aluminum folded skin, now most of the metal shell aircraft manufacturing technology is not very mature, but it will definitely be the future development trend of the aircraft. ”

"The F-13 outer skin is made of a lightweight copper-aluminum alloy just invented in Germany, which is wrinkled to increase strength, and the wrinkles are oriented backwards and backwards to reduce wind resistance. If you use a wooden fuselage, it will be difficult to find materials because future planes will be built bigger and bigger. The trunks and branches of trees that grow in nature can only provide wood of fixed size and shape; There is almost no limit to the characteristics and sizes that metal can provide, it is easy to process and form, reliable, the strength value can be correctly controlled, and it is not affected by weather and atmosphere. ”

"The monocoque fuselage can reduce the cross-sectional area by 35% compared to the traditional frame design, so it reduces the wind resistance, reduces the weight of the aircraft, and gives the aircraft a better surname, as evidenced by the fact that our aircraft can reach a speed of more than 230 kilometers per hour, otherwise, with the engine it uses now, it would not have exceeded 200 speeds." ”

"There are also monoplane cantilever gradually replacing double or even triple wing, and single wing can better reduce aircraft drag."

Then he said regretfully, "This will be the last wooden machine we designed, which is another reason why I made it from these materials." Yu Peng has long been doing theoretical research on aerodynamics, and his research has also proved the superiority of metal, single wing, and cantilever surnames, but he thinks that smooth metal skin will be better than the current pleated metal skin pneumatic surname, but the strength problem has not yet found a better solution. ”

When it comes to the technical problems of the aircraft, Ba Yuzao, an expert, has talked a lot, but this also surprised Song Zhewu, Ba Yuzao's judgment is completely correct, all-metal, monoplane, and cantilever are indeed the development direction of the aircraft in the future, although now there are more than 15,000 military aircraft in the world and none of them belong to this concept.

Song Zhewu couldn't help but feel a little itchy, and after thinking about the reason, he said: "Yunhua is right, if you want to design and manufacture a high-level aircraft, you must indeed have a forward-looking surname, and the starting point must be high, only if the starting point is high, you will fly high, so the aircraft we design in the future must adopt these latest technologies and concepts." When I was in Northeast China, I heard from captured Russian pilots that the American company Northrop had just developed a lower monoplane, which used a shorter landing gear that was tucked into the wing roots when flying. Due to the reduced flight resistance, the speed increases greatly. ”

"Wings retracted? That's right! This will definitely reduce flight resistance. Wang Xiaofeng also said in surprise.

Song Zhewu saw that the effect had been achieved, and after thinking about it, he said to Ba Yuzao, Li Minghua and Xiao Guodong: "Everything must have a plan, and with a plan, you can reasonably arrange the time and order of work, and the purpose is stronger." I think this is urgently needed not only for our aircraft development, but also for other scientific work. In my opinion, after the Spring Festival, presided over by Chief of Staff Xiao, each research institute must formulate a five-year scientific research plan, and then our various disciplines will jointly demonstrate, after the plan is formulated, all departments must invest manpower and material resources in strict accordance with the plan, you see how to ......"

(To be continued)