The canards, which are small wings at the front of the main wings of the aircraft, are actually equivalent to moving the horizontal tail of the tail of the aircraft to the front, because compared to the conventional layout of the horizontal tail at the tail of the fuselage, the canard wings can provide a lift coefficient for the aircraft together with the main wing.

That is to say, when the aircraft needs to do a maneuvering flight with a large elevation angle, the front wing, that is, the canard wing and the main wing will produce a strong vortex, and the coupling between the two vortices will be enhanced, which can produce greater lift than the conventional layout aircraft, so that the canard layout aircraft has an advantage over the conventional layout aircraft in terms of minimum radius turn, minimum radius circling and instantaneous angular velocity.

But the shortcomings of the canard wing are also very obvious, compared with the conventional layout of the aircraft, the nonlinear interference between the front wing and the main wing is very obvious, especially the aircraft with close coupling layout, the size, position and shape of the front wing have very strict requirements, a little improper, but will bring greater flight resistance to the aircraft, and at the same time will cause the abnormal aerodynamic characteristics of the aircraft, from another aspect to increase the design difficulty of the flight control system.

But there is no doubt that the close-coupled canard layout with a large swept delta wing has relatively little drag when flying at supersonic speeds, and is equally conducive to super-maneuverable flight maneuvers. At the beginning of the design of the J-20, it did not choose a conventional layout like the F22 and T50, but became the world's first fourth-generation stealth fighter to use a canard layout, which is one of the most important reasons, because at that time, compared with the developed countries in the West, the gap between our country's aero engine and the developed countries in the West was really too big.

In the case that the engine technology is inferior to others, it can only be compensated for by the design of the aerodynamic shape to a certain extent, which is also a helpless thing, which is much better than only running behind other people's butts and imitating without any innovation.

For the study of the canard layout, Cheng Fei can almost be said to be perfect, coupled with the experience of successfully developing the J-10, the J-20, which aimed at the F22 from the beginning, can be said to explode the opponent in terms of mobility, at least Xia Yu, who has been an opponent with the F22, can say so.

Suddenly pulled up the joystick, stepped on the rudder, the high-speed flying J-20 nose to the right, and then began to fly around the forward axis for a small radius drum, rolling forward a few times, J-20 immediately took a broken S and dived down until it was only more than 200 meters above the ground, and then Xia Yu immediately slowed down and flattened, the speed of the dive just now was too fast, and it exceeded the speed of sound again.

The roaring engine sound resounded over the entire airport, outside the airport wall, a group of military enthusiasts talked to each other excitedly, and the mobile phone used to shoot was steadily aimed at the J-20 that was flying at an altitude of less than 200 meters from the ground at the moment. It's not like I've seen it before, after doing one action, I always have to stop for a while before starting another action, although it's just as good-looking, but it's definitely not as exciting as today.

The excited enthusiasts chattered non-stop, but their eyes were firmly attracted by the J-20, and it was precisely because of this that the next flight made by Xia Yu make all the people who were watching this air show feel their scalps tingling and their hearts beating wildly.

What did Xia Yu do? In fact, it was not a difficult flight at all, Xia Yu was just planning to make this J-20 somersault. The broken S just made Xia Yu drop directly from a height of 2000 meters to less than 200 meters, after leveling, Xia Yu continued to control the J-20 to reduce the altitude, until it was only 15 or 6 meters from the ground before starting to fly level, but Xia Yu only flew for three or four seconds before pulling up the nose, J-20 was extremely quick to feedback Xia Yu's operation, and immediately began to roll vertically.

This is just a somersault, put on any air show, this kind of vertical somersault is just a routine performance project, but dare to play somersaults at this height, so far there are not a few, because once there is any error in the judgment of altitude, speed, angle and flight attitude, the result of the somersault is undoubtedly the result of falling down, that is, it smashes directly on the ground, becoming an expensive fireworks show.

This kind of example is not unusual, a few years ago at an aviation exhibition, the Russian Warrior Air Show Team had a similar example, the famous aerial scalpel Su-27 is not high enough after rolling down, directly hit the ground, and this kind of flight accident is not the first time it has happened, it is foreseeable, it will not be the last.

Therefore, when the somersault with a relatively small radius pulled out by Xia Yu passed the highest point, whether it was the military enthusiasts outside the wall, or Yang Wei, who was observing in the tower at the moment, he was chuckling in his heart at that time, and he was going to collide with the plane! That's what almost everyone who saw this scene thought.

In particular, Yang Wei, the chief designer of the J-20, was dumbfounded at the time. If this plane falls, it will be distressed at most, but if something happens to Xia Yu, this matter will become a big deal. Xia Yu is the X20 test pilot hand-picked by the second chief, this aircraft that is said to be very radical has not been detached from the design drawings, is its test pilot going to have problems first?

It is conceivable that once something really happens to Xia Yu, Yang Wei will not be able to escape the blame, and he will be punished for it. The punishment can be big or small, but these are all subsections, in comparison, Xia Yu's life safety must be put first.

No matter what other people think, don't dare to say anything else, for this flight action, Xia Yu dares to pat his chest and pack the ticket, as long as there is no problem with the plane itself, then there will definitely be no possibility of an accident due to his operation.

Therefore, under everyone's nervous gaze, the J-20 controlled by Xia Yu suddenly raised its nose in advance when the somersault turned to 270 °, so that the plane and the ground continued to slide in a parallel attitude of 90 °, and after completing the 360 ° somersault, the height of the J-20 was only less than ten meters from the ground, and then it seemed to pause in mid-air weirdly, and then swooped forward.

It was only at this time that a group of spectators just realized that the J-20 had no accident and got out of danger safely, but before they had time to take a breath, the J-20 suddenly raised to about 75 degrees in an instant when there was almost no change in altitude, and the wake from the two powerful turbofan engines shot directly on the ground, raising a large amount of dust, and the black-painted J-20A was like a pitch-black sword, piercing the sky.