"Regarding the transfer of the J-73 project to Chief Tu's side, I have actually made preliminary contact with him, and its meaning is also consistent with our conjecture, it is indeed intended to overhaul the existing J-7 aerodynamic design, maybe we can see the preliminary design plan released this year. ”

It does not take much effort to make a preliminary design scheme, only to give the pneumatic scheme and supporting subsystem according to the customer's requirements, and this stage relies on the designer's experience and wind tunnel data to "piece" the design and calculate the feasibility.

"Be sure that it is the RB-199 engine, this is what I promised to the north privately, otherwise they will not easily give up the South African cooperation project, the most important thing for the north now is the J-8 overhaul, and the RB-199 engine is their most optimistic power system, to say that I have also seen the improved J-8 made with this engine, which is not bad. ”

For the J-8 fighter that used to be his "child", Lao Wang now has an indescribable and unclear meaning, although it is not enough to say that the J-8 recognizes the thief as his father, this statement is a bit too much, but it is not a taste in his heart after all.

Of course, it was only after communicating with the northern institute this time that I found out that the Jian-8 of that year had long been a matter of fact, and the newly designed Jian-8 major reform plan still made great progress in the current view, which is worth rejoicing.

Lao Wang actually looked at the J-8 overhaul plan using the RB-199 engine, which is quite interesting, although the previous face successfully served the J-8 overhaul model, but that was the use of turbojet 13 as the power, and now it is replaced with the RB-199 of a whole era, there will definitely be a different result.

"Yes? What is the design scheme of the new Jian-8 major reform of the Northern Institute? If it is no problem, I am quite interested. ”

I really have some small expectations, after all, the RB-199 is used as an artifact, and the plan of the Northern Institute is the same as the design of the turbojet 13 engine, so Wang Zhengguo really wants to say MMP.

After thinking about it, Lao Wang felt that there was no need to keep it secret, and even the plan that the British would soon know should not be excessively secretive, and it would be okay to talk about it, after all, Wang Zhengguo would soon participate in the negotiations on the RB-199 engine project.

The bag took out a copy of the three views of the Jian-8 modification plan of the northern institute that was copied before: "Look at it yourself, the changes are still quite big, and even I can't see that it is an improved model of the Jian-8, but if it really has the help of the RB-199 engine and the British, I don't think it's a big problem." ”

When I opened the drawings, my first impression was that it was no different from the general design of the J-82, but the changes in the details were really not small, at least it looked more combative.

The nose is no different from the J-82, the air intake design and the J-82 using the turbojet 13 are quite different, the wing has also been modified, and as for the landing gear, it seems that it is still included in the wing.

To analyze the different designs brought about by the two different power schemes, it is first necessary to figure out which of the RB-199 family can be obtained this time.

The RB-199 project comes from the joint research and development of Britain, Germany and Italy, and in the early years it was only to meet the requirements of the Tornado multi-role fighter, so the 7.2 tons of thrust is the most profound memory of this engine by the outside world, is this the RB-199 with 7.2 tons of thrust?

I'm afraid the situation is not easy to say, careful analysis, if you just look at the RB-199 engine promoted by Rolls-Royce this time, it must be the MK104 type, as the power system of the Tornado ADV, with a bulky reverse thrust device, there is still a thrust data of up to 7.98 tons, shamelessly, it can be said that it is 8 tons.

The J-8 will definitely not need a thrust reverser, so what will be the result if the thrust reversing device is removed?

In fact, the British really had such an engine, numbered RB-199MK104D, which was used in the early prototype test flight of the Typhoon fighter, and the thrust-to-weight ratio reached 8.26 The amazing data, which directly realized that the Typhoon prototype at that time broke through the sound barrier at low altitude without afterburner!

As for why the British recommend this quasi-8-ton thrust MK104, instead of the slightly backward but awesome 7.2-ton MK101, the reason is that MK101 belongs to the three countries to invest and benefit together, if this engine is recommended, the money earned by Rolls-Royce can only get 40%, and the MK104 program is a wholly-owned design by the British, and all the money earned falls into the pockets of the British.

In contrast, as long as Rolls-Royce is not a fool, it will definitely sell the MK104 type, think about this thrust data of nearly 8 tons, it is really not too good, what turbojet 13 is only 6.6 tons of thrust, or how far you go!

Now that you know what kind of engine you can get, if you think about it, it's not that you can't guess the reasons for the above design.

For example, the design of the air intake, due to the lack of thrust of the turbojet 13 engine, and the J-8 series must meet the volley operation, the J-82 on the upper plane is insufficient in power and pneumatic compensation, and the bee waist fuselage is used to reduce supersonic resistance, which leads to the concave air intake in the middle of the fuselage, which seriously squeezes the fuselage space.

Now there are more than 13 turbojet RB-199 streets, absolutely rich in power, in this case, there is no need to use a complex bee waist fuselage, a little more violent, a little simpler, directly use a straight-through design similar to the Su-15 fighter air intake, how good!

Of course, the use of this straight air intake is actually related to the fact that the air flow of the RB-199 is larger than that of the turbojet 13, and only when the new air intake is more efficient, this can meet the actual needs of the RB-199 engine.

Even if the aerodynamic drag is a little larger, it can't stand the thrust of others, even if it is simply through the air intake, the fuselage space liberation it brings, whether it is oil or equipment, is completely a major benefit.

Looking at the wing design again, the simple delta wing inherited from the MiG-21 is gone, replaced by a double delta wing scheme, this design is also the technical route of the later improvement of the Su-15, in order to optimize the maneuverability at low altitude / low speed, it seems that a certain institute is indeed ambitious.

Both of these improvements are at the cost of increasing aerodynamic drag to gain more fuselage oil space, low-altitude/low-speed performance, and in this respect, they are indeed related to the RB199's high-thrust performance.

As for the landing gear, Wang Zhengguo also studied it carefully for a long time, only to find that this guy has indeed made improvements, although the connection point between the landing gear and the aircraft is also designed on the wing, but the position of the wheel nacelle has changed.

The J-82 landing gear using turbojet 13 is retracted forward, which seriously occupies the valuable hardpoint on the inside of the wing, the reason is very simple, the turbojet 13 is relatively long, resulting in the engine occupying more inlet space, and when the landing gear of the J-8 is retracted, the wheel part is included in the outside of the intake tract, which can only be retracted forward, and it has to occupy the space on the inside of the wing when it is retracted forward.

The size data of the RB-199MK-104 engine is completely different from that of the turbojet 13, this guy is only 3.6 meters in length, yes, only 3.6 meters, compared with the 4.6 meters long data of the turbojet 13, it is completely one meter less in length, in fact, this is another explosion data of the engine.

The length of the engine can be greatly shortened, which will inevitably bring the air intake tract to continue to extend backwards, and even the wheel storage compartment of the landing gear can be moved back by at least one meter, which frees up the space for the inner wing pylons of the J-8 to RB-199 scheme.

Originally, it could only be mounted on the inner hardpoint of the close-range combat bomb, but due to the change of the landing gear retract position, after the inner space was increased, it was no problem to hang medium-range bombs, aerial bombs, and even the YJ-8 series anti-ship missiles, which was simply an awesome explosion, which may be the reason why the Jian-8 in the early 80s said that it could reach the ground.