As the military put forward more and more requirements, Lin Hongfei's brows also wrinkled: according to these requirements, the requirements of Universiade have exceeded the limit of the Il-62M, and there is no problem in expanding the fuselage of the Il-62M to the extent of the Il-76, but now, it has reached the level of being one size smaller than the Bian-124...... This is an exaggeration.

In this way, the stakes become extremely great!

But despite this, while the risk has become greater, it also means that if it can succeed, it means that it is possible to have two large transport aircraft, one military and one civilian, and AVIC Group 2 will form a more complete aircraft product line, but if it fails......

"Comrade Lin Hongfei, is it very difficult?" Looking at Lin Hongfei, who was frowning, Ding Kexue was a little worried.

"The problem is not small...... Lin Hongfei nodded, this is not the time to be modest, "According to the current requirements, the size of the fuselage is close to the shortened fuselage of the U.S. military C-17 transport aircraft, but the length of the fuselage is a little shorter, but the width and height of the cabin are similar...... I need to think about it. ”

C-17 transport aircraft close to the Americans? Everyone was taken aback by Lin Hongfei's words: How is this possible?!

But when everyone recalled the revised requirements again, they couldn't help but be silent: indeed, as far as the fuselage is concerned, it is indeed similar to the C-17 transport aircraft, but the fuselage length is a little shorter, and the maximum load and maximum take-off weight are a little smaller......

C-17, this is the most advanced large transport aircraft in the world, much more advanced than the Il-76, we ...... Is it really possible to develop such an airplane?

Lin Hongfei didn't say that no one had paid attention to this yet, but Lin Hongfei's words woke everyone up, and in an instant, there was a strange tranquility in the conference room that was still a little warm just now: everyone almost listened to the Americans boast about the advanced point of the C-17 transport aircraft. But through all aspects of information to understand the strength of this aircraft, with our country's industrial strength, can we really develop a large transport aircraft with performance close to the C-17 transport aircraft?

"Actually...... We also have a reference object......" A voice rang out in the room.

Swish~~!

As if hearing a silent order, all eyes converged on the person who spoke, even Lin Hongfei was no exception, and looked at the guy who spoke in amazement: How could it be him? This person who was specially approved to attend the meeting by AVIC Group 2 kept his mouth shut from the very beginning of the meeting and did not speak, but now he actually spoke?

"Mr. Li, you said you have someone you can refer to?" Ding Dachuan's eyes lit up instantly!

Lin Hongfei's gaze was even more eager. "Chief Master Li, do we have such a reference object?"

"Yes," Li Zaijian, the chief designer of the Y-8 transport plane, the only largest military transport aircraft in the Republic today, nodded to the leaders present very respectfully at this moment. "Mr. Lin, I think. We can refer to the An-218. I have listened to our army's requirements for the new large transport aircraft, the An-218 in terms of fuselage structure is more in line with the requirements, we have obtained all the design data of the An-218, if the An-218 as the prototype to develop this military transport aircraft, our design work is equivalent to 50% of the completion. ”

An-218? An-218! There seemed to be a fire exploding in his head, and Lin Hongfei couldn't wait to slap himself twice: yes! How did I forget this!

This is actually a grievance against Lin Hongfei. It was not long before the An-218 data was brought back, and after the An-218 was brought back during the Moscow Air Show, it was still in the data sorting period, and Lin Hongfei was full of cards that he could play. It's entirely possible to forget that you still have such a good card in your hand.

Speaking of An-218, there is a small episode in this, at the beginning Lin Hongfei thought that An-218 was a level of aircraft with Boeing 767 and Airbus A330/A340, but after a preliminary analysis of the data, he realized that he had lowered the positioning of this aircraft: where is this cargo Boeing 737, Airbus A330/A340 level aircraft, this cargo is a typical "Boeing 777sky"!

The diameter of this cargo fuselage is even larger than that of the Boeing 777, and the structure is not a pure prototype of the Boeing 777, but an oval shape similar to an egg standing upright on a tree, with a width of 6.2 meters on the left and right sides of the fuselage, but a staggering 6.8 meters in height up and down!

Because it is now in the period of data collation, it will take about one and a half to two years to complete all the data collation and verification, and at the same time, there is also a lack of an opportunity to establish a project for this large aircraft of the same level as Boeing 777, Lin Hongfei automatically forgot about this aircraft in his mind, but now Li Zaijian reminded the chief designer, Lin Hongfei suddenly realized: Yes! Isn't An-218 the best prototype?!

Although only a physical model of the 1.1 was completed, the main design work and the design of the flight control system were completed, and the subsequent work was followed by the construction of prototypes and test flights to test what still needs to be adjusted and modified.

"An-218?" Ding Dachuan's eyes are equally bright and scary!

AVIC No. 2 Group is analyzing and sorting out and verifying the data of the An-218 that they obtained at the end of the collapse of the former Soviet Union to fight against the Boeing 777, and he naturally knows the truth, but he, like Lin Hongfei, also made the same mistake: subconsciously left the An-218 behind, and now with Li Zaijian's reminder, he also immediately realized this, for the An-218 that has basically completed the design and manufacturing work and entered the prototype manufacturing stage, It is indeed the best reference object, and it can even be said that the new Universiade has completed 50% of the design work.

Glancing at Lin Hongfei and seeing that Mr. Lin signaled himself to answer, Li Zai briefly organized the language, and then said, "Yes, I am the leader of the data collation team, based on the existing information, I know very well the level and technical content of the An-218, and it is also feasible to develop a large military transport aircraft similar to the C-17 on the basis of the An-218, but there are still many problems......

"What's the problem! Just say it! Without waiting for Li Zaijian to finish speaking, Ding Dachuan said to Li Zaijian, and he almost patted his chest.

"Now there are three biggest problems, one is the problem of the engine, at the beginning of the design of the An-218, it was planned to use two D-18T large bypass ratio turbofan engine modifications: D-18TM, but the engineering of this improved model of the engine was canceled with the collapse of the Soviet Union without much progress;"

"Engine ......" Ding Dachuan suddenly frowned: The engine is a big problem, without an engine, even if you build an aircraft that can carry 10,000 tons, it will be useless. He frowned for a long time, and finally asked Lin Hongfei, "Xiaolin, didn't you get the information on the PS-90A engine from the Soloviev Design Bureau?" ”

"That engine is not stable enough, even the Russians haven't found a solution to the problem now," Lin Hongfei knew what he wanted to say, and shook his head without waiting for him to finish speaking, "But I prefer to use four improved models of D-30K engines, I believe that after such a period of use, the leaders of the Air Force have enough understanding of the D-30K engine, which is a very mature small bypass ratio turbofan engine, with stable performance and reliable operation, The only downside is that the thrust seems to be somewhat lacking. ”

Four D-30K? Today, the Prime Minister and the heads of the Air Force looked at each other and nodded: the idea seemed very feasible.

"In response to this situation, we are preparing to carry out two improvement plans on the basis of D-30K, one is to improve the compression ratio through technical improvement, and the performance is roughly the same as that of the D-30KP used on the Il-76MD, with a maximum thrust of 13 tons; Another model is conceived to expand the bypass ratio on the basis of D-30KU, according to our calculations, this scheme is safer, the core machine is more stable, under the condition that the core system remains the same, by expanding the bypass ratio from the current 2.0 to 4.5 to 5, the maximum thrust will be able to increase to about 16 tons, and the new engine can also do 80% of the parts and D-30K common. ”

"I personally tend to increase the thrust by expanding the bypass ratio, compared with D-30KU, the fuel consumption of the new engine has not increased significantly, but the thrust is greater, which is equivalent to saving a lot of fuel, which can be used in the field of civil aircraft, and it is also the least difficult to achieve technology."

"This ...... Have you already reported the improvement plan? Ding Dachuan frowned and thought for a while before asking Lin Hongfei uncertainly.

"Well, it didn't take long......"

Ding Dachuan's old face suddenly turned red: Lin Hongfei said that it didn't take long, it was to give himself face, if he remembered correctly, it seemed that it had been handed over for almost half a year, "Comrade Hongfei, do you think this improved model of engine can be used on our large transport aircraft?" Isn't it a bit risky? ”

"D-30K is a very mature engine, the main technology has been mastered by us, if this engine scheme is adopted, we are sure to come up with the first prototype within two years, because the core machine and D-30K are exactly the same, so I think reliability and safety are still trustworthy, of course, if the military is not at ease, we can still use the bypass ratio of 2.0 D-30K ......"

As he spoke, he glanced at the results he had just calculated on the notebook in front of him, "My calculation is that if you use D-30K, if you can optimize the shape enough, you can achieve a maximum load of 55 tons to 60 tons, but the range is ...... I can't guarantee that the maximum payload of the aircraft can be increased to 75 to 80 tons using an improved model with a bypass ratio of 4.5 to 4.8. ”

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PS: On April 1st, the first day of this month, the millennium will work hard for three more, two more guarantees, and one more to repay the debt, brothers, ask for a guaranteed monthly pass! (To be continued......)