Republic of China: Ace Pilot

Chapter 681 The concept of the helicopter emerges, and the self-propelled individual flight device.

The plane landed at the seaplane base in northern Myanmar. It was already sunset, and night was about to fall.

Fang Wen stepped off the plane.

Lu Zexuan, the director of the Taishan Research Institute, who was waiting at the airport, came over and said, "General Manager, after receiving your telegram, we have notified them, and they are all waiting for you in the conference room now."

Fang Wen nodded and strode away from the seaplane airport, saying as he walked, "The technical discussion tonight might take a long time, so have the cafeteria prepare some late-night snacks and send them over."

“Okay, I’ll arrange it in a bit,” Lu Zexuan replied.

After exiting the seaplane airport, walk 600 meters east along the main road of the base, and you will reach the Taishan Research Institute.

Fang Wen followed the rules he had set for himself, showed his identification for inspection, and was then allowed to enter.

After entering, he went directly to the third floor of the main building of the research institute. The lights were on in the conference room, and many people were already seated there.

The chemistry research group led by Huo Duanyang.

Jiang Wenjin's rocket research group.

There were also key technical personnel from the No. 2 Aircraft Manufacturing Plant brought by Lin Yifei.

And other trusted technical personnel.

Upon seeing Fang Wen enter, everyone quickly stood up, curious about the content of the technical seminar to be held that evening.

Fang Wen walked to the head of the table, put his briefcase on the table, and took out the hypothetical draft of the individual soldier flight device: "This technical seminar involves military secrets. Considering that our base in northern Myanmar has already experienced two incidents of Japanese spies infiltrating, in order to prevent leaks, I did not invite any foreign experts. I also hope that everyone present will remember the confidentiality agreement of Taishan Military Industry and absolutely not disclose any content of this meeting or subsequent research and development."

After he finished speaking, Lu Zexuan and his office staff distributed supplementary confidentiality agreement guarantee letters to each participant.

Everyone signed their names on the guarantee.

At this point, Fang Wen finally spoke up: "Alright, this technical seminar is now officially starting. I'm going to launch a very challenging project. Here are the project hypotheses; please circulate them and take a look."

Fang Wen handed the draft of the individual soldier flight device to Jiang Wenjin, and then it was passed around from person to person.

After everyone had finished reading, Fang Wen said, "If anyone has any questions, please ask them now."

Lu Zexuan opened his meeting notebook and began recording the entire discussion.

Jiang Wenjin spoke first: "General Manager, for single-person flight... where will the power come from? Right now, the size and weight of our engine is a big problem, and with the external structure added in, it feels like the overall size and weight of the aircraft won't be reduced much."

After he finished speaking, he looked at Huo Duanyang, who waved his hand and said, "Our chemistry group will not comment."

Lin Yifei spoke up: "We just discussed it, and the only way to achieve this is to streamline the entire aircraft, reducing its size and weight. Only in this way can we use a smaller engine, thus making a single-person aircraft possible. Actually, one of our engineers has proposed a similar solution, and I think we can have him talk about it."

Fang Wen was surprised that someone was already doing research in this area. But then he understood. The research atmosphere at the No. 2 Aircraft Manufacturing Plant was very open. Wasn't the Huashan Type 1 civil airliner developed by the No. 2 Aircraft Manufacturing Plant itself? He hadn't been involved in it.

He shook off his thoughts and nodded in agreement.

Lin Yifei looked at a young man beside him: "Lu Chengzhi, you speak."

Lu Chengzhi stood up, somewhat shyly: "Good morning, General Manager, and good morning, comrades. My idea comes from an article in the *Huaqing Journal* entitled 'Leonardo da Vinci's Scientific Thought.' When I was at Southwest Associated University, I read this article while researching in the school library. The article analyzed the mechanical model of helicopter propeller flight. Later, after joining Taishan Military Industry and accumulating engineering and technical experience, I wondered why airplanes couldn't take off in helicopters. Therefore, I submitted a report to the factory director requesting research on helicopter flight, and the factory director agreed."

Upon hearing this, Fang Wen became somewhat excited. Wasn't this a helicopter?

He said, "You should come up here and, if possible, draw a sketch to help everyone better understand your research."

With the general manager's approval, Lu Chengzhi's cheeks flushed with excitement as he walked to the blackboard behind Fang Wen.

Grab the chalk and quickly sketch on it

"We'll install a rotating propeller on top, two meters in diameter, which will be enough to generate lift. The key is the power! I've calculated that we need an engine with at least 60 horsepower and a weight of no more than 80 kilograms. Our existing piston engines are too heavy, so we need to modify them. We'll reduce the number of cylinders to four and increase the compression ratio. That should work."

“Weight reduction is easier said than done!” Jiang Wenjin suddenly interjected, pushing up his tortoiseshell glasses. His tone was scholarly and rigorous. “A four-cylinder engine doesn’t have enough power. If we force the compression ratio up, the cylinder block’s heat resistance won’t be able to keep up, and it will explode after flying for less than ten minutes. Foreign engines have been pursuing increasing the number of cylinders to improve engine performance for years because they can’t solve the compression ratio problem. Of course, if we achieve that, it will be even more effective in fighter jets.”

Lu Chengzhi's face flushed instantly, his hand gripping the chalk trembled slightly, but he still stubbornly retorted: "We can use chromium-molybdenum alloy steel imported from the United States! The materials group's report said that this steel has better heat resistance than ordinary chromium-molybdenum alloy steel. I've calculated that using it to make the cylinder block will result in a higher explosion resistance rate."

"Even if the engine block material is improved, the compression ratio is still a problem. How can it be solved?" someone asked.

Fang Wen, who had been listening, spoke up: "The compression ratio issue can be resolved. Our Taishan Military Industry already possesses the technology for turbocharged engines. Now that the conditions are ripe, we can directly implement this technology and develop it together with the individual soldier flight device."

As a result, the researchers became even more eager and actively engaged in the discussion.

Fang Wenze looked at the sketch on the blackboard and pondered.

Although engineer Lu Chengzhi proposed the basic concept of a helicopter, there is still a long way to go before it is realized.

Helicopters generate lift by cutting through the air at high speed using a rotor; the rotor is both a lift component and a control component, and can achieve takeoff, landing, and steering by changing the rotor pitch.

This is not a simple aircraft to operate; its control method is quite complex. The time required to train a helicopter pilot is about the same as the time required to train a fighter pilot, and it requires extremely high operational precision.

The frequent helicopter accidents in India are largely due to the inadequate skills of the pilots.

Therefore, this helicopter technology can be a research direction, but it is not the kind of individual soldier flying combat device he wants.

While Fang Wen was pondering, the researchers were also having a heated discussion about the new helicopter.

The discussion focused on how to operate this aircraft.

"Use steel cables for transmission! Referring to the aileron control of fighter jets, three control sticks are installed in front of the pilot's seat: the left stick controls elevator, the right stick controls steering, and the middle stick controls throttle. The propeller speed difference is adjusted by a gearbox."

Jiang Wenjin, however, changed the subject to another discussion.

“Helicopters require a lot of power, which I don’t think is suitable for individual soldier aircraft. But this design gave me an idea: why not use the power generated by the airflow to drive the rotor?”

"What do you mean?"

The researchers stopped their discussion and all looked at Jiang Wenjin.

Fang Wen also stopped thinking and looked over.

Jiang Wenjin drew a diagram on the blackboard and explained: "From an aerodynamic point of view, after an airplane takes off, if we don't consider speed, it can use the airflow to drive a horizontally rotating propeller, thereby generating continuous lift. The engine mainly generates thrust during takeoff and when the airplane turns forward or backward. In this way, although the performance of the airplane is reduced, its practicality meets the requirements mentioned by the general manager."

Not all the researchers here understand aerodynamics, so Jiang Wenjin used a vivid way to explain it.

"Have you ever played with a bamboo dragonfly? A bamboo dragonfly only needs an initial spin to fly; it works on the same principle. We install an engine within the bamboo dragonfly structure to generate thrust, allowing it to take off and change direction in the air." The researchers, who were unfamiliar with aerodynamics, immediately understood.

Fang Wen was also invigorated, recalling a type of small civilian aircraft from his future memories.

(Gyroplane)

The core feature of this aircraft is that its rotor is not powered; it generates lift by rotating due to the airflow in front of it. Its flight principle is fundamentally different from that of a helicopter, and it has a simple structure and high safety.

It's just slow, so it's only a plaything for the private sphere.

It seems feasible to use this type of aircraft for individual combat operations, as long as it's not a frontal attack, there are many opportunities to utilize it.

Thinking of this, Fang Wen also got up and walked to the blackboard.

“Your suggestions are excellent. I’ve incorporated your ideas into the design.”

He picked up the chalk and drew a sketch on the blackboard.

"The individual soldier's flight device can be extremely simplified, consisting of only three parts. The first part is the lift structure, an autorotor mounted on top of the fuselage, but without a power transmission system; it is only connected to the rotor shaft via a hinge and can rotate freely. The second part is the propulsion system and cockpit, with a propeller engine located at the rear of the cockpit, providing only forward thrust and not driving the rotor. The third part is the tail and landing gear; the tail is used to control direction and stabilize attitude, and the landing gear is wheeled, which allows for short-distance takeoff."

After he finished speaking, the researchers continued their discussion around the blackboard.

This time, we're discussing how to implement Fang Wen's design.

Although it was late at night, they still maintained plenty of energy for their discussion.

Lu Zexuan closed his meeting notebook, put it away, and left.

After a while, he came in with his office staff carrying food boxes.

The late-night snack prepared for the seminar has arrived.

A new research team was established overnight.

Fang Wen personally served as the project leader, and the team members were drawn from various research groups and the No. 2 aircraft manufacturing plant.

The research site was set up in the No. 2 aircraft manufacturing plant, where a manufacturing hangar was requisitioned.

The first important task after the establishment of the individual soldier flight device project team was the selection of materials.

This type of lightweight aircraft is defined for special operations; as long as the airframe is sturdy, it is acceptable, without considering ballistic protection.

Therefore, lightweight materials are the primary choice.

The propeller was the first thing the team made.

The material used is spruce.

Spruce is recognized as the best timber in the aviation industry. It has a density of only 0.42 g/cm and a bending strength of 110 MPa, which is 30% higher than that of ordinary pine. It also has a uniform grain and is not easy to crack. It has been used for the main wing spars of P-51 and Spitfire fighter jets.

It is also a good sparsity material for rotors, which can significantly reduce the weight of the blades while ensuring strength.

The beams are made of Sichuan spruce wood, with maple and mahogany laminate filling, and the front edge is reinforced with a thin brass plate. The outer impact-resistant layer is made of 2 mm aerospace-grade aluminum alloy.

To ensure that the blade structure does not fall apart under high-speed rotation, phenolic resin adhesive, which was previously purchased from the United States, is used for bonding, along with stainless steel blind rivets, to ensure a seamless fit between the frame and the metal layer.

The blade skin is made of premium French linen aviation fabric with a warp and weft density of 200 threads per inch, which is 50% stronger than ordinary cotton and linen fabric. It also has low extensibility, which allows it to conform to the airfoil curvature of the blade and has excellent abrasion resistance.

After the propeller blades were made, Fang Wen had his team install them on a specially designed rotating mechanical structure, using the high-speed rotational power generated by the 12-cylinder engine to simulate aerial spinning.

The blade structure remained intact during prolonged rotation, so it passed the test.

Next came the cockpit and tail section.

The cockpit features a lightweight outer shell, while the tail fin shell is made of 2mm aluminum alloy with an internal wooden structure and a special steel frame.

As for the landing gear, it is a fixed type with a steel structure frame and rubber tires.

With all that done, the next step is the power system.

This is also the key to individual soldier flying vehicles.

The old-fashioned aircraft engines had enough power, but they were too big and heavy to be suitable.

In reality, individual soldier aircraft do not require a 12-cylinder engine; even an 8-cylinder engine would be too much. A 4-cylinder engine would suffice.

But efficiency must be improved.

To this end, Fang Wen began to develop a new type of turbocharger.

In the engineering laboratory.

Fang Wen started the engine and activated his supernatural abilities at the same time.

The black, deformable material in the engine is transformed into different shapes under his control to test how to better modify it.

After hundreds of physical deformation simulations, he designed the device based on the collected data and then personally manufactured the turbocharger components.

Two days later, the finished parts were assembled and transformed into a mechanical component only the size of a fist.

This sophisticated turbine mechanism was connected to the compressor and installed on the engine for testing.

After the engine started, Fang Wen smiled. He had succeeded. The device had achieved the effect he wanted, increasing the power of a single cylinder by 35%.

This improvement means that the Taishan engine will undergo a major transformation.

Simply put, it's like overclocking a future computer CPU, where a 3000 Hz CPU can be overclocked to achieve the effect of 4000 Hz.

In the field of engines, turbocharging can transform a 10-cylinder engine into a 12-cylinder engine.

This is still a change made to an engine that already uses some turbocharging technology.

If a naturally aspirated engine uses this new turbocharger, its power can be increased by up to 60%.

(End of this chapter)