The test pilot is a veteran driver who has been flying the Jianjiao-7A for hundreds of hours, and although this Jian-74 looks a little different from the Jianjiao-7A, this is not a problem, it is much the same.

Sitting on the plane, the familiar feeling hit again, and even felt that the whole body was full of power, after all, the turbofan 10 equipped with this aircraft is much stronger than the turbojet 7, and it is already a world difference in performance.

The engine started again, and the test pilot could clearly feel the surging power of this engine, after all, it reached a maximum thrust of 7.2 tons, and even the roar of the engine heard now was much better.

Wearing an oxygen mask and an American-style load-resistant suit with quite good protective performance, it seems that this J-74 fighter is very different from the previous fighters of the Republic, but when the test pilot raised his hand and raised his thumb to indicate that he was about to take off.

Yang Hui saw something shocking through the telescope, white woolen labor protection gloves, this thing is simply a tumor, hovering in the Republic of China's navy and air force aviation for decades, destroying the overall sense of science and technology, this is really

Well, Yang Hui admits that the military labor protection gloves woven from cotton thread do feel very comfortable to use, and they are indeed easier to use and more flexible than those leather gloves in Western countries, especially some old pilots, who have been accustomed to this thing since the aviation school.

Yang Hui even knew that in later generations, the army of the Republic also issued handsome leather gloves to pilots, but many pilots were still reluctant to use them, and still loved labor protection gloves.

Shaking his head, he could only comfort himself: the protective gear of gloves does not have much impact, and the choice of protective gear is based on the premise that the pilot is comfortable and flexible. This is a feature of the Celestial Empire, as long as you get used to it.

Keep looking at the past. The plane has been accelerating and sliding, and the engine spews bright flames, indicating that it is now working stably, and this time it can be clearly seen that the glide distance of the aircraft is much shorter than that of the previous Jianjiao 7A.

Watching this first aircraft fly into the sky, Yang Hui fell into thought, and now the design of this aircraft should be no problem. The engine has been tested intensively for so long and will not fail under normal circumstances.

The only thing that made Yang Hui feel a little inappropriate after reading it was the tail nozzle of this turbofan 10 engine, which did look a little too backward.

In the development of turbofan 10 engine, there are high-temperature turbines, combustion chambers, continuous air leakage technology research, the risk is actually very large, based on these considerations, in the tail nozzle design of turbofan 10 engine, and continue the old-fashioned simple convergence nozzle technology adopted by turbojet 7 and turbojet 13.

Listening to the name, you will know that this tail nozzle is relatively simple in structure. As we all know, the structure of mechanical equipment is simple, and in many cases, the effect is relatively poor, and the simple convergence nozzle just confirms this.

Essentially, the simple convergence nozzle used today is a fixed nozzle cross-section, which can only optimize a fixed flight speed range. However, in different flight speeds, the tail nozzle section requirements of the engine are different, and the simple convergence of the nozzle naturally cannot be improvised.

This simple converging nozzle. It was quite popular in the early fifties and sixties, when most of the aircraft were subsonic and subsonic. Rarely flies to hypersonic speeds, which is naturally a good option.

The engine tail nozzles used in the planes that really want to fly to Mach 2 and Mach 3 are pilot nozzles (for example, the P31 engine used by the MiG-29 is the pilot nozzle), and these tail nozzles are naturally adjustable nozzles, which can be adapted to the changes in the flight speed of the aircraft.

In Yang Hui's plan, the J-74 and J-75 both gave up high-altitude and high-speed. Keep up with the international mainstream to fly at medium and low altitudes, operate in the low-hypersonic and subsonic speed ranges, and be more offensive multi-role fighters.

Aircraft designed based on such operational requirements naturally do not have a high maximum flight Mach number, and there are almost no more than Mach 2. The use of simple convergence nozzles on this can be regarded as making the best use of things and making the best use of talents.

In fact, when the simple convergence nozzle is Mach 1.5, the thrust loss is only about 14 percent, which is relatively mediocre in the efficiency of many tail nozzles, and there is no problem with the J-74 and J-75.

According to the experience of many years of use, the thrust loss of the simple convergence nozzle can reach 30 percent when the aircraft flies at a speed of more than Mach 2, and the thrust loss will be as high as 50 percent when the aircraft flies at Mach 3.

Such a large thrust loss, Yang Hui doesn't want to be like this engine when it is used in high-altitude and high-speed interceptors, what will it look like, even if it does not fly in the speed range of Mach three, but as long as it exceeds Mach two, the simple convergence of the nozzle is almost a drag oil bottle, which is absolutely unbearable.

Of course, it is not uncommon to find this kind of strange design in the world, for example, there is such a strange design in the Republic, in the Republic of J-8 fighters, the early model uses a turbojet seven engine, which is a typical simple convergence nozzle.

Even the J-8 II fighter in the previous face, the turbojet 13 engine used is still simple and convergent, as a high-altitude and high-speed interceptor designed in the eighties, such a design is simply laughable.

Of course, the Dawn Factory, which is responsible for the development of the turbojet 13, announced it to the outside world, but it was the same thing: simple convergence, and the tail nozzle is adjustable.

Listen to this completely out of tune: since it is simple and convergent, and you also have an adjustable tail nozzle cross-section, are you going to be a fool for everyone?

It can be seen how clumsy this kind of propaganda is just for the sake of propaganda, and how clumsy it is to fool the layman, if it doesn't work, you just don't introduce it, and everyone feels better.

The current turbofan 10 engine once again continues to use a simple convergence nozzle, which is no problem in the J-74 and J-75, which do not pay attention to high-speed flight.

However, the turbofan 10 was taken to the Dawn Factory for production, and it was to be installed on the J-82. It is difficult for Yang Hui to imagine what kind of situation it will be, and whether the Dawn Factory will spend some effort to improve the tail nozzle of the turbofan 10? It is more suitable for the use of J-8.

"Hey, what will I do to save you, our big brother Dawn"

After a long sigh, I forced myself not to think about it, now is the big day of Southwest Science and Industry, and the first flight of J-74 is still quite important.

"Chief Master Yu, this first flight is coming to an end, and it seems that it is another successful first flight."

Yang Hui is happy, Chief Master Yu is also full of emotion, since 83 years, has been constantly changing the old Jianqi, until now it has been changed even its mother does not know it, the ups and downs in the middle, and how many people have seen the efforts, everyone is for every successful flight.

Feeling the hardships in the improvement process, Chief Master Yu also sighed: "Who said it wasn't!" We have invested so much money, so much manpower, and even some scientific researchers are tired in their posts, so there should be no problem with the first flight of this aircraft."

Chief Master Yu didn't say what he said later, but everyone knew it. No one can say that a complex mechanical equipment will not have problems if it is reasonable, and no one can guarantee that there will be no problems with precision equipment.

As the wheels and the runway came into close contact, a screeching sound came, which meant that the plane had landed safely, and when I looked over the runway, I saw that the speed of the plane had slowed down, and the flames from the engine were no longer dazzling.

"Okay, the first flight was successfully played, we can discuss another big thing, the J-74 is a multi-purpose combat aircraft, no longer a training aircraft, and the weapons and equipment are much more than the J-7A."

Speaking is the naval boss Commander Liu who is standing next to the chief division, he is very optimistic about this light and offensive J-74, after the success of the first flight, the development of weapon systems needs to be put on the agenda. (To be continued......)