Cao Huajun's complaint Xia Yu naturally couldn't hear it, even if he heard it, Xia Yu might not necessarily complete his test flight task in full accordance with the regulations, as long as he felt confident, he dared to do it, which was Xia Yu's disadvantage and Xia Yu's advantage. Without such an adventurous spirit, I'm afraid that Xia Yu would not have achieved what he is today even if he had the help of the starry sky.

Flying over the runway, Xia Yu immediately pulled the control stick back after judging that he had gained enough altitude and speed, and the control stick of the optical transmission system allowed Xia Yu to use only two fingers to gently flick it back to complete the control of the aircraft, and the aerodynamic surface changed by 1801 immediately responded to the air resistance, and the raised nose exceeded the stall critical angle of attack almost instantly, and became the nose facing the sky, and the posture of using inertia taxiing forward with the belly facing forward.

This is a stall action, or half a stall action, because limited by the aerodynamic shape, 1801 can not raise the nose of the aircraft more than 90 degrees or even form a tail rush like the Su-27, but even so, the angle of attack roughly around 80 degrees has made the flight control system automatically issue a stall angle of attack warning, the sound of "beep" sounded, and the plane was also rapidly reducing its speed, and at this time Xia Yu did not level the plane, but began to set the flight mode, Changed to VTOL mode.

On the ground, Cao Huajun's eyes widened, his mouth opened wide, and he was extremely surprised to see that the 1801 in the sky suddenly opened the top cover of the lift fan with his nose facing the sky, and at the same time, the bottom of the tail nozzle was also opened, which scared Cao Huajun half to death at that time, and the angle of attack was too large, which would have caused insufficient air intake in the engine. At this time, turn on the lift fan to enter the vertical take-off and landing mode, isn't that looking for death? What should I do if the engine stops at a surge?

Xia Yu's behavior completely subverted Cao Huajun's cognition. Cao Huajun even thought that there was a problem with the flight control system, so he picked up the microphone and shouted: "1801." Your plane is out of order, the lift fan is on, and you're going to stall! ”

Xia Yu naturally heard Cao Huajun's voice, but at this time, Xia Yu's control of the plane was entering a critical moment, so he didn't answer immediately, this flight action was consciously completed by Xia Yu, so he was quite sure in his heart. It can be seen from the fact that the lift fan was turned on and started, but the tail nozzle was not deflected downward, and the current attitude of the aircraft was still in Xia Yu's expectations.

The lift fan is turned on. The agitated differential pressure air flow was immediately sucked in by the rotating fan blades, and then converted into thrust to eject from under the belly, and the auxiliary air intake of the main engine had been turned on, because the air intake had been greatly reduced, and the thrust provided was also greatly reduced, and the roll control nozzle did not work efficiently, but still provided a certain deflection torque for the 1801. At this time, Cao Huajun was already crazy, because in Cao Huajun's eyes, 1801 was after turning on the lift fan. The posture of the whole aircraft began to become extremely strange, and the nose continued to slowly rise more than 130 degrees while tilting to the left, as if it was turning a lazy waist in the air, rolling horizontally 180 degrees, turning into a gliding posture with the dorsal fin facing forward. With the completion of the horizontal roll, the attitude of the angle of attack of more than 130 degrees just now has become a strange state of positive 70 degrees of attack and minus 110 kilometers of airspeed.

I look at it almost while I am crazy about dropping heights. At the same time, he completed a 180-degree vertical roll of the plane, and Cao Huajun felt that he was going crazy. If nothing else, the engine may have started to surge. The next thing that should happen is to stop in the air. What does it mean to stop the engine in the air without airspeed, that is a 100% crash, Cao Huajun no longer thinks about saving the plane now, and it is very lucky to be able to crash in the airport instead of outside the airport.

Picking up the microphone, Cao Huajun didn't hesitate too much, and immediately shouted: "1801, skydive, you have no altitude." ”

"Skydiving? Why? Xia Yu, who didn't know that he scared Cao Huajun to death, looked inexplicable after hearing the content of the communication, although the plane was falling altitude, it was not in a stall spiral state, and the engine was in less than a second of surge, because the airspeed of the plane was reset to zero while completing the leveling, and the barely enough air was regained, and there was no air stop. And although the current situation is that 1801 is falling straight down, but that is because the thrust provided downward has not yet resisted the inertia of falling downward, as long as the engine can provide continuous reverse thrust for the aircraft, the aircraft can complete the deceleration before falling to the ground, and re-enter the hovering state, that is to say, the plane is very safe, Xia Yu didn't understand why Cao Huajun suddenly called himself to parachute, could it be that there was something wrong with the plane?

Quickly observed all parts of the aircraft through the distributed photoelectric aperture system, Xia Yu looked dazed, there was no problem with the plane! Xia Yu, who thought it was better to confirm it, immediately asked on the radio: "Command vehicle, this is 1801, the plane's data is normal, and it is making a vertical landing, why do you want me to parachute?" ”

All the data is normal?! Cao Huajun opened his mouth wide and glanced at the technicians around him, especially Luo Hao, the test pilot of 1801, who looked at Cao Huajun in disbelief, as if he saw the news of the alien attack on the earth yesterday in the news network, but was defeated by the indigenous tribes of Africa with blow arrows, which made no sense at all.

Although he didn't understand what was going on, Cao Huajun immediately grabbed the microphone and asked, "1801, are you sure that the current data of the plane is normal?" The engine doesn't stop? Didn't there be a problem with the flight control system? ”

Xia Yu glanced at the multiplexing display and replied: "There is really no problem, the flight control system is normal, the engine is working normally, and the current descent rate is under control." ”

Looking at the 1801 that was still falling straight, Cao Huajun was stupid, what made him even more stupid was that the falling speed of 1801 was indeed slowing down, and when 1801 fell to more than 100 meters from the ground, it had almost formed a hover, and the descent rate was so low that it could be seen with the naked eye, and when 1801 was only thirty meters above the ground, he finally stopped the downward trend, forming a perfect hovering state, and then put down the landing gear in Xia Yu's control, and then descended smoothly and slowly, The landing was finally completed.

When the landing gear of 1801 touched the ground at the same time, and then stopped, Cao Huajun instantly felt that all the sounds were far away from him, and in Cao Huajun's eyes, at this moment, except for the plane that had landed perfectly and was taxiing towards the tarmac, there was no room for anything.

I can't figure it out, I really can't figure it out. As the person in charge of the test flight team, Cao Huajun himself has participated in the design and development of the 180 project, and he is undoubtedly clear about the design performance indicators of the aircraft. It is impossible for the experimental data of the wind tunnel group to be wrong, the previous attitude of 1801 in the air will definitely cause the engine to surge due to insufficient air intake, and the continuous surge state will undoubtedly cause the engine to stop in the air, but why did it not happen this time?

Cao Huajun's brain was all immersed in deep thinking, so much so that when Xia Yu turned off the engine and jumped off the plane and walked towards him, Cao Huajun didn't notice it at all.

"The deflection rate of the lift fan should be adjusted again, and the power of the compressor should be increased by about eight percent, so that the action can be completed in advance, and the engine will not have a chance to surge." Xia Yu said as he approached: "This should be regarded as a controllable stall action, in the face of a sudden slowdown, it is easy to be able to include the other party in the attack envelope when you want to bite your own enemy aircraft, I think there should be no other aircraft that can do it except this aircraft, well, it should be regarded as 1801's exclusive air flight technology, but the current response is still a little slower, and after the flight control system is optimized and the hardware is improved, it should be possible to make a faster response action, Only then can it be regarded as a complete stall fighting technique. After saying that, Xia Yu nodded quite smugly, not noticing Cao Huajun's look of hell at all.

"What did you just say?" Cao Huajun was suddenly very excited, grabbed Xia Yu and asked.

was taken aback by Cao Huajun's reaction, but Xia Yu still replied: "I said that the deflection rate of the lift fan should be adjusted again, what's wrong?" ”

Cao Huajun ignored Xia Yu's question, and suddenly realized: "I see, I understand." It must be that before the engine surge occurs, the air attitude of the aircraft is just to complete the vertical roll of 180 degrees, and then reduce the fan thrust, improve the main engine thrust that has completed the deflection and provide thrust downward, and accelerate the adjustment of the aircraft attitude leveling, and at this time, the inertia climb of the aircraft has also reached a critical value, and the airspeed is zero, just so that the aircraft is in a relatively stable air environment, which can provide sufficient air intake for the engine, which is why the engine does not have surge and air stopRight? ”

After saying his words in one breath, Cao Huajun looked at Xia Yu with blank eyes, hoping to hear a positive answer from Xia Yu's mouth, which was already the most reasonable flight process he could think of. Xia Yu didn't deny Cao Huajun's speculation, but he said unconsciously at all: "That's roughly the case, but after you say it, how do you feel that this is an uncontrollable and dangerous action?" ”

"Is this still not a dangerous move?" Cao Huajun rolled his eyes: "This is a single-engine plane......" (to be continued......)

PS: Thank you for the tips from the remnant soul disillusionment, Tiangao Yundan 925 and TXZG brothers, thank you for your support ^_^