"The altitude is 13000, the course is 110, the speed is 770, and the action can be started."

"Understood, you can start moving."

The voice of the girl in charge of communication in the ground control tower came over the radio, and after Xia Yu replied that he understood, he began to prepare to do the flight maneuver as planned.

Turning on the afterburner, Xia Yu is ready to enter supersound. The familiar feeling of pushing the back hit again, Xia Yu first successfully entered the supersonic speed, and after the speed was increased to Mach 2.2, he turned off the afterburner and exited the supersonic state, and then prepared to carry out the second supersonic speed again, this time it is necessary to observe the stability of the transonic regional stage, so it is necessary to maintain a certain speed to control the flight time. Xia Yu is ready to enter the transonic zone again.

The transonic zone is an aerodynamic term that refers to a range of speeds just above and below the speed of sound, about Mach 0.8 to Mach 1.3.

"The speed is Mach 1.2, the body reacts normally......" Xia Yu reported the flight number jù, and suddenly, the fuselage of the plane that had been flying steadily shook several short times in a row, Xia Yu only felt as if the whole person was about to be thrown out at a glance, and the huge inertial force made Xia Yu's head hit the cockpit cover a few times, and his arm was also pulled and involuntarily rammed around. Fortunately, this was only a momentary thing, so although it happened very suddenly, Xia Yu quickly calmed down and began to check the status of the plane.

There is no need to look at it, just the reaction of the airframe let Xia Yu know that the output power of the two engines has become zero, and he immediately controlled the flight attitude of the aircraft, and then began to contact the tower: "Tower, this is 09, my two engines have stopped." Repeat, both of my engines stopped. ”

Xia Yu's report made the ground tower tense, and the air stop was a great threat to the J-31 designed by the static Dìng, and if the speed was lost too much before the engine restarted, it was likely to fall into a spiral and lead the way down. If the malfunctioning aircraft cannot land completely, the scientific researchers will not be able to study why the aircraft will fail, and no one will dare to guarantee that the next aircraft will not encounter the same problem, which is a very severe blow to the test flight team. In addition, research funding is limited, and it is not uncommon for some demonstrators to lose the opportunity to continue research and development after being dropped.

"The engine restarted successfully." At 5,800 meters above the ground, Xia Yu successfully restarted the engine, and everyone on the ground breathed a sigh of relief when he heard this.

The test pilots want to fly, all of which are such planes with endless failures, Xia Yu has long been used to it. When he was first selected to test fly the J-31 before, he had encountered such a situation many times, so it didn't cause him too much psychological pressure. Successfully landed the plane on the ground, Xia Yu began to explain to the technical engineer on the ground the operation process of flying in the sky and the situation encountered when parking, and the ground engineer on the side hurriedly recorded what Xia Yu said, these are all information that must be collected.

After finishing what he should do, Xia Yu left the test flight base, if he wanted to take off again, it was estimated that it would be two days later, and Xia Yu was not in a hurry. He got the news before that an improved J-20 verification aircraft of Chengfei was transferred here for ground adjustment tests a few days ago, and it will start test flights today, so he plans to go over to have a look.

came to another runway, because he was also a test pilot, although he was a different affiliation, Xia Yu was not stopped in the end, because Feng Huaixin, the person in charge of the test flight of the J-20, specially approved it after learning that Xia Yu was the test pilot of 31009. The 31009 verification aircraft fought with the F35 at sea and drove away from each other, which has already been rumored in the industry, and it is rare for a test pilot with actual combat experience and the latest fourth-generation aircraft to come over to watch, Feng Huaixin also wants to hear Xia Yu's evaluation of the J-20.

"The inspection is complete, and it is ready to take off."

The voice of the J-20 test pilot came from the radio, and then I heard the communication girl in the tower allow the J-20 to take off, Xia Yu and Feng Huaixin stood on the edge of the runway, watching the huge body of the J-20 accelerate and taxi on the runway, and then raised the nose of the plane and slashed through the sky like a huge horse chopper.

"How?" Feng Huaixin put down the intercom, turned his head to look at Xia Yu and asked with a smile, "How do you feel about the climb of 20 compared to 31?" ”

"So how can I see that if I fly, I might know some specific differences, but it looks like the thrust of the engine should be above 9." Xia Yu pointed to the J-20, which was almost climbing vertically, and said: "Otherwise, even if there is a ternary vector nozzle, this flip speed should not be so fast." ”

"Well, you're right." Feng Huaixin nodded and said: "Because the WS-15 has made a breakthrough, the thrust-to-weight ratio is close to 10, according to the news from the yàn room, at most in half a year, we should have a real large thrust ratio aero engine, so that the final shape of 20 and 31 is not far away." ”

"20 is okay, if a certain type is produced, the Air Force will definitely purchase it." Xia Yu pursed his lips and said: "As a carrier-based aircraft, the purchase volume of 31 by the Navy must be pitiful, and it is estimated that the equipment of itself has not been sold much." ”

Feng Huaixin shook his head and said: "I don't know how many 31 the Navy can procure, but because you drove the 31 and actually did it with the F35, the number jù collected later also shows that the combat performance of our 31 is not worse than that of the F35, so once the final engine is replaced, in addition to the bomb load and fuel load are not as good as the F35, with the flight performance of the 31 against the F35, our pilots are not false at all, just rush this point, the 31 purchased by the Navy will definitely not be less, At least one-third of the total number of aircraft carrier-based fighters on the entire aircraft carrier. ”

"That's the problem." Xia Yu said: "We now have no other aircraft carriers except for a Liaoning that is being trained, according to the current research and development progress, once the 31 is finalized, we will not use so much, I estimate that next year or the year after, the production version of the 31 should appear at the air show waiting for the transaction." ”

While the two were chatting about the sky, they were also paying attention to the J-20 flying in the sky, and after steadily climbing to an altitude of 8,000 meters, this latest J-20 began today's test flight action, climbing, circling, somersault, and after the subsonic basic combat maneuver was done, it began to conduct supersonic tests. The conversation between the J-20 test pilot and the ground tower can be heard by Xia Yu because of his relationship next to Feng Huaixin, but because he is not part of the J-20 test flight team, Xia Yu is not good at interjecting.

Thinking of the sudden stop of the engine at transonic speed before, and then thinking of the engine that this 20 has just been replaced with new materials like his own 31, Xia Yu waited for Feng Huaixin to end the conversation with the pilot and said: "When I tested the 31 in the morning, at transonic speed, the engine suddenly stopped, you know? ”

"Huh?" Feng Huaixin was stunned for a moment, and asked: "I've been preparing for today's test flight in the morning, but I haven't heard of this news, but it's good that you can come back safely, have you figured out the reason for parking now?" ”

"Not yet." Xia Yu shook his head and explained: "My 31 is also a new material engine that has just been replaced, the subsonic action is very normal, the engine response is very sensitive, and there is no sense of lag. However, when I was doing supersonic speed, in the transonic region, when I maintained an airspeed of Mach 1.3 for 6 seconds, the engine suddenly stopped, and the altitude was reduced to 5800 meters before it was successfully restarted. Because it was two stopped at the same time, the inspection after going to the ground showed that there was no abnormal situation such as the oil circuit, so I suspect that there is a new problem on the core machine, 31 and 20 are the same core machine, so I think it would be better to remind you, I hope you don't blame me for many things. ”

"No, no, no." Feng Huaixin shook his head again and again and said: "Your suspicion is not unreasonable, and your reminder is very timely, the situation you encountered may be an example, but we can't ignore it, you just said that the airspeed is maintained at Mach 1.3 and stops in the air after 5 seconds, right?" ”

"Yes."

"I'm reminding Lu Lehui and letting him be prepared."