In Chengdu, Qin Feng gained a lot, watching the rapid progress of various technologies, and a sense of infinite pride surged in his heart, and after returning to the test flight base from Chengdu, the test flight continued to begin.

"Now, one of the most critical test flight subjects is low-altitude and large speed." The chief pilot officer said: "This subject is very dangerous, and as the time gets colder day by day, the speed becomes more and more difficult to achieve, and the further you go, the higher the risk." ”

Qin Feng had flown at low altitude and high speed in the past, and knew how great the danger of this project was.

Now, the average fighter can reach Mach 2 and reach more than 2,400 kilometers per hour, but this speed is obtained at high altitude, after all, the air resistance at high altitude is small, and at low altitude, the maximum speed is sharply reduced.

At low altitudes, due to the high density of air, when flying at supersonic speeds, the air flow will have a strong impact on the fuselage skin, and even bring structural damage, and the most dangerous thing is that it may disintegrate in the air, which will cause flight accidents.

When an airplane disintegrates in the air, can a person eject out? Of course it is impossible, in that case, man and the plane are one, and when the plane disintegrates, the person will disintegrate with it.

So, does that mean that there is no need for the plane to make such a dangerous flight?

Of course not, low-altitude and large-speed is of practical significance, and this is low-altitude and large-speed penetration, which is a commonly used means in modern warfare.

In the past, there was a pursuit of high altitude and high speed, there were indicators of double three, and there was even a monster like the Blackbird reconnaissance plane, but with the passage of time, this pursuit changed.

High-altitude and high-speed does not guarantee perfection, because anti-aircraft missiles can continue to develop, and at the same time, high-altitude and high-speed are not easy to carry out precise attacks on the ground, at most it is just a reconnaissance.

With the restriction of high-altitude and high-speed penetration, more and more ways have begun to switch to low altitude, and only at low altitude can we avoid the opponent's radar and use blind spots to penetrate the defense.

Not only fighters, bombers have begun to penetrate at ultra-low altitudes, but also a lot of technology, the advanced aspect, is the use of terrain matching radar, and even cross-linked with the aircraft's control system, in case the pilot can not react, can automatically help the aircraft pull up, to avoid hitting the ground.

Although the J-10 is a fighter, it can still be equipped with ground attack weapons, and this is also one of the design indicators, according to the plan, it is at low altitude, can fly to a maximum speed of 1450 kilometers per hour, even if the engine can push it to fly so fast, it is necessary to see if the body can withstand it, especially the skin, in case the skin can not withstand such a large air pressure, it will be damaged.

"In the past, we have flown to a low-altitude target of 1,160 kilometers per hour, and the aircraft is in a stable state and there is no problem, but now, we mainly continue to increase the speed from 1,160 kilometers per hour, and constantly test the safety of the flight envelope." Song Lao followed and said, "Now, let's give this task to Tang Gang." ”

"Old Song, I'll come." Qin Feng said: "My body is already well, besides, I haven't flown for so long, I can't wait, after all, I don't have much time to fly." ”

Qin Feng was almost at the age of grounding, and when Old Song heard his words, he could only nod.

In the past, when Qin Feng was flying Jian-7 and Flying Leopard, he had flown at low altitude and high speed, and he was quite experienced, but now, after accepting the task, Qin Feng immediately entered the test flight.

If the test flight site is sufficient, then the afterburner can be turned on at low altitude and continuously accelerated to exceed the speed of sound and reach the required speed, but in this case, the required airspace is too large, and in order to complete the test flight in a small airspace, a special way must be used.

There are strict restrictions on low-altitude and large speeds, flying at supersonic speeds, and the nose piercing the sound barrier will bring a huge impact on the ground, and if there are animals below, it will cause serious consequences, for example, if you fly over a chicken farm, the chickens in it will almost all die.

So, you can fly at low altitudes, but you definitely can't just go into supersound.

Then, if you want to complete it in a small airspace, you have to use a special way, which is dive acceleration.

Climb to a high altitude first, and then dive down, so that you can use gravitational potential energy in exchange for kinetic energy, you can increase the speed of the fighter, which is a common means of test flight.

When he returned to the cockpit again, Qin Feng was still quite excited, he really couldn't imagine the life of the grounded flight in the future, perhaps, he could only enjoy it on the simulator, right?

Qin Feng looked at the monitor in front of him, at this time, there was already a feeling of disgust, no way, compared with the cockpit of the Thunder Dragon fighter, the scientific and technological level of the J-10 was not enough, or the strength of the Thunder Dragon.

Turn on the engine, afterburner took off, as before, at an altitude of four thousand meters, Qin Feng pushed the operating stick, and the fighter began to dive downward.

The speed was getting faster and faster, and the body was shaking with the plane, and then, an umbrella-shaped shock wave cloud appeared in front of the nose, piercing the sharp cone and entering the supersonic region.

At this time, the earth was coming, Qin Feng looked at Ping Xian, one thousand, one thousand, one thousand, one thousand!

Qin Feng leveled the plane, and the first test flight ended like this, go back, check the overall state of the plane, there is no problem, and then continue the test flight, one thousand one, one thousand two, one thousand three!

After a few days of test flights, the speed continued to increase, and soon reached a speed of 1,350, but a new problem arose.

"We are now using a 20-degree dive, in this way, our kinetic energy is limited, so we can never accelerate to the predetermined speed, let alone 1,450, we can't even reach 1,44." Qin Feng looked at the experts present and spread his hands helplessly.

Even if the afterburner is fully turned on and the speed is down, it still can't make a breakthrough in speed.

Even if you increase the height, it is useless, this complex aerodynamic drag is definitely not proportional to the speed, with the increase of speed, it will gradually be proportional to the square, the three, and the fourth power of the speed, which means that after the speed reaches a certain value, it will be more and more difficult to continue to increase the speed!

Qin Feng already had this feeling when he was flying in the past, and now, hearing his words, the experts present were also helpless: "Yes, the last hundred kilometers are the biggest challenge for us, Qin Feng, what can you do?" ”