To say that the father of the double delta wing is this Dragon fighter produced by the Swedish company Saab.

The so-called double delta wing refers to the ordinary wing is a pointed triangle shape, and the wing sweep angle is a fixed value, while the double delta wing is more like a structure that combines two different triangles, such as the Dragon fighter, the inner side is a wing with a sweep angle of 80 degrees, and the wing body fusion design with large thickness provides sufficient space for accommodating fuel and the main landing gear; The outer wing section is a small delta wing with a thin airfoil, and the leading edge sweep angle is 57 degrees, and the design of the outer wing section is conducive to improving the low-speed ability of the fighter and shortening the take-off and landing distance, while retaining the low-drag special surname when flying at high speed; The vertical rear wing also has a swept design.

Because the Dragon fighter is a tailless delta wing layout commonly used in the West, while the J-7 is a normal aerodynamic layout of wings and tails, the two are not the same.

"Our fighter also needs to be modified into a double delta wing shape, with a sweep angle of 57 degrees on the inner wing, a sweep angle of 42 degrees on the outer wing, and a mobile flap on the front and rear edges should be added. Zhang Feng said as he gestured.

didn't tell the other party about this improvement at the beginning, not because Zhang Feng deliberately concealed it, but Zhang Feng had to first determine whether the other party would really make up his mind to improve, as long as the other party made up his mind, then of course he would tell the other party what he knew.

However, this knowledge, Zhang Feng knows, was originally the other party in a few years later can sum up, in history, until the late eighties, the chief designer of the J-7E, Tu Jida's student Lu Yingyu made a bold attempt, introduced the research results of Professor Sha Bonan of Northwestern Polytechnical University, and creatively changed the original delta wing to a double delta wing, and equipped with front and rear edge maneuvering flaps, which greatly improved the maneuverability of the aircraft. At the same time, it was replaced with a new high-power engine, and the maneuverability of the J-7 was raised by a notch, far exceeding that of the MiG In fact, Zhang Feng was equivalent to plagiarizing their research results, but anyway, it was applied to the original object, but it was only a few years late.

"Your Excellency Qusay, you have a wealth of knowledge." Song Wencong said, "We didn't expect that you were so knowledgeable, and both of us were ashamed of ourselves. ”

"Where, where." Zhang Feng said: "The use of this wing structure also needs to be redesigned, using the wing integral fuel tank, so that the fuel storage capacity of the aircraft will be increased, to ensure that this kind of fighter with turbojet engines has enough range." ”

The overall fuel tank of the wing refers to the sealing of the internal space of the wing to form a fuel tank structure, which can increase the fuel load by nearly 50% and increase the range.

"If our fighter can finally be put into mass production, then the surname Neng will definitely have a qualitative leap on the original J-7." Tu Jida said.

"yes, this fighter, should it be given a new name?" Song Lao also said.

"This fighter, surnamed J-7, can be surpassed in an all-round way, I feel that it is good to call it Super Seven." Tu Lao said: "Our internal project code is called Super Seven. ”

Super Seven? Sure enough, the history is still strikingly similar! Zhang Feng thought in his heart, looked at the scene outside the window, and said: "Our aircraft factory has arrived. ”

Originally, this production line of his own company must be strictly approved before it can be visited, but the agreement with these Chinese is almost even if it is reached, they will come here in the future to install and test flights of fighters, moreover, this production line is already very backward for the United States, it is the F-5 production line modified, so Kashin did not raise any objections.

At this time, all kinds of equipment in the huge factory building are being installed and debugged under the guidance of American technicians.

Although it was backward equipment imported from the United States, it was still very impressive for the Chinese visitors, and the workshop for the production of fighter jets in China at this time was still very backward.

For example, in the large workshop for the production of aircraft girders, there is a large piece of equipment: a CNC machine!

The aircraft girder is the main stress part of the aircraft, which is equivalent to the spine girder of the human skeleton plays a vital role in the flight of the aircraft, and the uneven processing of the wall thickness of the girder will directly affect the flight surname of the aircraft, and the quality of the girder processing directly affects the flight safety of the aircraft. For example, due to processing errors, the strength is reduced in some places, then, in the fierce air battle, a large overload may cause the aircraft girder to break, and the fuselage will also be broken into two sections.

On this set of girder production equipment, Zhang Feng sent the negotiation team, also spent a lot of effort, Northrop company, began to only provide finished girders, do not want to provide processing equipment, because this CNC machine tool is quite complex processing machine, but also the United States strictly controlled the export of processing tools.

If you don't provide processing equipment, what is the production line! The two sides negotiated for a long time over this issue, and finally reached an agreement: the United States would provide the forged beams, and the Iraqi side would carry out the machining.

The girder is first pressed into the required shape by a large hydraulic press, and then cut, so although Northrop promised to be very generous and output the production line, in the specific problem, it is still trying to hinder.

The Iraqi side agreed, and Zhang Feng knew that obtaining a set of CNC machine tools meant a great development of Iraq's processing level.

However, when this set of machine tools arrived, Zhang Feng knew that he had been tricked by the other party again.

This set of CNC machine tools, an old-fashioned machine tool with a history of nearly ten years, does not use a microprocessor, and there is actually an electron tube in it!

However, the knife is not old, no matter how backward this set of machine tools is, it is much better than the old-fashioned machine tools that are manually controlled and completely based on their own experience.

Zhang Feng can only hope that this set of machine tools will be adjusted and played to the best state, so here, the workers he sent are also the best, a few of them have come back from abroad, understand this technology, and the Yankees can't fool it.

"What is in front of you is our company's most advanced processing equipment." Kashin was unashamed to introduce these Chinese: "If your aircraft girder needs to be processed, it can also be done through this equipment." ”

"Can you machine titanium alloy beams?" At this time, a man in the crowd asked.

Titanium alloy? Kashin frowned: "Of course it can be processed, but the titanium alloy girder is relatively expensive and not suitable for this kind of light and cheap fighter." ”

Titanium alloy girders, that is high-tech in fighter jets, so it is impossible to export these technologies, and the F-20 uses only ordinary aviation high-strength aluminum alloys. On the F-20, titanium alloys are mainly present in the engine, however, the engine is imported in its entirety.

Walking forward, all kinds of equipment dazzled the Chinese personnel, and all of them felt the gap with the other party.

Walk up to a workshop where the Americans are training Iraqi mechanics on how to rivet skins.

The outer skin of the aircraft, not welded, is constructed with rivets.

Although this group of technicians has been trained for half a month, they are still far from meeting the requirements, and they are busy on their own small model.

Even punching a rivet can reflect the gap! Because, on Chinese fighters, those rivets can be clearly seen, as if they were patched, very conspicuous.

In their eyes, those rivets can be nailed on, but now, the technicians are very strict, riveting, grinding, and finally painting, which will blend in with the surroundings.

Constantly improve something!

While this group of Chinese was visiting the aircraft production line, on the other side of the Zubayer city, another group of people was also busy.

The atmosphere is relaxed on one side, and very tense on the other.

Although they are not very far apart, Iraq has done a very good job of secrecy, with a large number of soldiers patrolling to ensure that there is no interference between the two tasks.

Liang Lao had no idea that the domestic delegation was coming again, and he was still working with Iraqi technicians to develop a new type of cruise missile.

In the early stage of the test flight, the habitual navigation system and the terrain matching system have been able to work normally, and now, what they need to do is to enlarge the missile body, and then free up the part occupied by the solid-fuel engine for liquid fuel to occupy, and the tail part is a small turbojet engine, and an additional air intake is added.

Cruise missiles do not need to do too many high-overload actions, and most of the time, they are stable in flight, so the technical difficulty is not very great.

Moreover, at this time, the domestic C802 missile was also under development, so the team led by Liang Lao carried out a lot of reference work and greatly accelerated the progress.

The cruise missile finally designed has a total length of 7.3 meters, and excluding the booster rocket engine at the rear, the missile is 6.1 meters long, the diameter of the missile is 0.4 meters, and the total weight is 800 kilograms.

At the beginning of the development of this missile, it was considered that it could be mounted on most of Iraq's active aircraft, and when launched from an airplane, it did not need to carry a rocket booster at the back, and had a range of 320 kilometers, while when launched from the ground, it had a range of 280 kilometers.

Joseph's current work is very easy, because the design of the missile body is not under his control, as long as the Chinese side manufactures the missile body and connects it to the guidance system he designed, it can complete the manufacture and carry out test firing.

This time the turbojet engine arrived, and they are carefully installing the turbojet engine on the missile body, refueling, energizing, and on the test bench, preparing to conduct several experiments first, and then conduct live-fire experiments after they are correct.

(To be continued)