Now, the domestic military aircraft research is still at the level of the sixties, and the only successful self-development is the J-8, the design of this aircraft is a comprehensive imitation of the J-7.

In addition to the nose air intake, another feature is the tail cover used in the tail of the aircraft.

Aerodynamic studies have shown that the tail of the aircraft should also become a streamlined structure, so as to reduce the flight resistance, so when the jet was just beginning to develop, this tail cover was quite popular.

It wraps the engine tightly and forms a streamlined shape at the back, so that the dimensional rectification is carried out.

At the same time, this can make the tail introverted, and the tail nozzle airflow can be directed to improve the thrust, so this thing is called the tail cover of the ejector.

In fact, this thing is very inconvenient, because it is in the high temperature area and the tail, it is easy to be damaged, in order to facilitate replacement, it is often used to partially fix with the fuselage, partially detachable connection type, the outer skin is mostly aluminum alloy, the inner skin is heat-resistant alloy, or all heat-resistant alloy.

It is precisely because of this cover that the J-7 is designed to become the form of the overall disassembly of the rear fuselage, if it is on the J-7, how much can it be used, then on the J-8, due to the lack of scientific design capabilities, this kind of ejector tail cover is not only very heavy, but also can not actually play the role of the ejector tail cover, it will only lose thrust in vain.

Even in the Soviet Union, this tail device is the result of a mixture of the designer's past experience and subjective speculation, and lacks rigorous scientific and engineering basis.

Later, the Soviets conducted another experiment, remodeled the old model and compared the flight test work, studied the tail cover of the projector, and found that this thing was not very useful.

So, in the nineties, with the technical assistance of Russian experts, the tail of the J-8 has been removed.

Now, the design of the third-generation aircraft has begun to adopt this form, the engine is directly mounted on the tail, and on the engine, it has an adjustable convergent-expansion nozzle, and this kind of ejector tail cover is no longer used.

This also makes the disassembly of the engine quite simple, and now, in the eyes of everyone, four technicians have easily removed the engine, just placed on the trolley platform below, the complex pipeline of the engine, so for the first time in front of everyone, and then, everyone watched them push the fighter away, the engine was perfectly presented.

Think about it in China, it is the fuselage in front of the aircraft that does not move, and the fuselage after hoisting, even if it is in the workshop, there is a crane overhead, and this hoisting is also a test of technology.

But what about people? I actually changed my way of thinking and put several tons of engines on the cart below, but the cart did not move and pushed the fighter away, so it was okay!

Don't look at the fighter planes are heavier, but on the ground, as long as it is horizontal, a dozen people can push the fighters away, which is very easy. Song Lao looked at his watch, 17 minutes!

It only took 17 minutes to complete the workload of the day, and this design must also be used on the new annihilation of the own side, which will greatly facilitate the field maintenance operation.

The four ground crews, under the field airfield, can quickly complete the replacement of the engine, and it is certainly not difficult to install it if it is removed so quickly.

Just after putting the engine on the cart and showing it to everyone, the four technicians took a short break there, and three minutes later, they started again.

Installation!

Installation is the reverse process of disassembly, and the order of disassembly is opposite, however, the time is not the same, it is very simple, dismantling a nut, it is definitely simpler than installing it, if the location is special, maybe it takes a lot of effort to complete the task of installation.

Several people are very skillful, and what they show is a special beauty of the aviation industry, and everyone is stunned!

Everyone watched the fighter retreat slightly, gradually covering the engine, which was like directly stuffing the engine in, this way, greatly reducing the difficulty of installation!

The cart can also be moved, the engine is accurately stuffed into the determined position, several people continue to install it, and finally, the skin that was disassembled below is re-equipped, and the engine is installed, which takes twenty minutes!

"It was an eye-opener." Mr. Gu also sighed on the side that there is a big gap between his own fighter design and other people's in thinking.

The other party attaches great importance to the maintenance of the ground, which I have actually seen during the inspection before.

Western fighters and avionics equipment are all plugged in, and if you want to dismantle a small transponder, you have to dismantle it from the top, layer by layer, and toss for a long time, this is the gap.

"Of course, our engine has its drawbacks." Seeing the surprised eyes of the crowd, Boileau said: "Now, its thrust-to-weight ratio is not high. ”

As a turbofan engine, the M53 engine has a thrust-to-weight ratio of only 5, which is the same level as the Spey engine and the TF30 engine.

This is mainly due to its single-rotor design, which results in a low compression ratio. The M53 has a compression ratio of 9.8:1, compared to the 30:1 compression ratio of its contemporaries GM F110 and Pratt & Whitney F100.

The fuel consumption of this engine is quite high, with a fuel consumption of 0.9 per unit thrust without afterburner, while this value is usually about 0.7 for similar military turbofan engines.

Due to the lack of engine thrust, the thrust-to-weight ratio of the whole aircraft of the Mirage 2000 cannot reach 1, which greatly limits its mobility, and if there is an advanced engine, then this fighter will be even better.

Boileau also had to explain in advance: "Now, we are also stepping up the development of the M53-P2 engine with greater thrust, its maximum state thrust will be increased by 18 percent to 6,550 kg, the engine weight will be reduced by 20 kg, the engine thrust-to-weight ratio will be increased to 6.6, and the take-off thrust-to-weight ratio of the "Mirage" 2000 aircraft equipped with the M53-P2 engine will be increased by seven percent to 0.9. ”

Although the take-off thrust-to-weight ratio is less than 1, it is already very high to 0.9, and when it flies to the destination, part of the fuel consumption can reach 1 in normal air combat.

The specific data can't fool people, but you can draw a pie for the Chinese guests and tell them that there will soon be a newer engine, which can greatly improve the performance of this fighter!

"Yes, we are eye-opening this time, in the past, it was simply sitting in a well and watching the sky." During the delegation, some people sighed.

Boileau smiled secretly in his heart, it seems that there is no problem with the exit this time.