In the real room of the China Gas Turbine Research Institute, a WS-15 turbofan engine is firing an almost translucent light blue tail flame, which has been running smoothly for 3,200 hours, another has been repeatedly started up to 850 times, and another is repeatedly turned on afterburner, and the ternary vector nozzle has been undergoing life tests.

These WS-15 is the use of the latest high-temperature alloy formula to develop, the tests have all reached the design parameters, the thrust-to-weight ratio has reached 9.8, although the final design finalization requirements are that the thrust-to-weight ratio must reach more than 10.5, but the gradual maturity of the high-temperature alloy formula has made the researchers in the research institute happy. According to the current progress, soon, the J-20 will be able to truly have a powerful heart and become a fourth-generation fighter that can truly cruise at supersonic speed.

While the gratifying progress of the big push made the researchers of the institute flutter, they did not forget to submit the alloy formula to the research department of the middle push. The R&D progress of Zhongtui has been lagging behind, because the country's attention is focused on Datui, so this is also an inevitable thing. But the engine, as long as there is a technological breakthrough, can share research results in a certain way, in other words, it is basically universal, especially the core machine.

I'm afraid many people don't know that the compressor with the CFM56 engine on the Boeing 737 that they are used to is actually used in the engines of military fighters such as F15E and F16.

The same is true for materials and processes. While the newly obtained high-temperature resistant alloy formula has greatly improved the performance of the Emei engine, the researchers responsible for the Zhonghua engine Taishan WS-13 will naturally not miss such an opportunity. Although the country's attention is not here at present, as scientific researchers, they have not forgotten that there is another fourth-generation stealth fighter developed by Shen Fei that is still waiting for its most powerful heart.

"Check in." The month-long vacation passed quickly, and there were no other waves in between, except for the accident of the bank robbery. After Xia Yu and Ye Zi separated, they came to the test pilot institute again.

Although the test flight unit is subordinate to the Air Force, the test pilots to which they belong do not actually need to participate in the daily flight combat training tasks, and most of the test pilots are directly involved in the test flight work after graduating from the test flight academy, and only a few people like Xia Yu have entered the test flight institute from the army.

Test pilots are also a type of researcher, but the risks they face are higher than those of combat pilots. From the first flight of a new aircraft to the design finalization, there will be an average of one failure every 17 minutes during the test flight, what air stop, surge, spiral, avionics system failure and other dangers are countless, and the plane that fell during the test flight is also countless, so the loss of personnel and property is astronomical, but this is the work of the test pilot, any new aircraft is installed, it is inseparable from the hard work of this group of adventurers.

Xia Yu is now also one of this group of adventurers, the 31009 he is responsible for has undergone many small modifications within a month, and he should have been ready to start test flights when he came back from this vacation, but the breakthrough progress of high-temperature resistant alloys directly interrupted the original plan.

Remove the current engine and replace it with a new WS-13D.

Changing the engine of the aircraft is a major operation, and it is not simply removed and installed, but fortunately, the 31009 is equipped with WS-13 from the beginning, although it is an overall replacement, but there is no need to do too much rectification, as long as the engine is loaded, re-test the center of gravity, and then you can start the test.

The test results showed that the center of gravity did not change much, and the first start of the engine was next. Xia Yu sat in the familiar cockpit, performed the inspection procedure before the engine started, found no problems, and gave a thumbs up to the ground engineer to indicate that the actual start test could begin, and Xia Yu pressed the ignition switch.

The harsh and familiar engine sound came, the WS-13D was successfully started, under the wing, the technical engineer has been in communication with Xia Yu, and the inspection items such as the adjustment of the oil output size can only be taken care of by the technical engineer on the ground. After the ground test was completed, Xia Yu turned off the engine and waited for the engine to cool down before conducting another inspection.

Coming down from the escalator, Xia Yu took the technical reference Wen Jiàn in his hand, and said to Wang Yifu with a smile: "The Wen Jiàn said that the thrust-to-weight ratio of this new engine has reached 9.6, and the service life of the binary vector nozzle has also been increased to 320 hours, and it has finally barely gotten rid of the name of the ground crew nightmare, haha." ”

Wang Yifu shook his head helplessly, and said with a smile: "This is barely a huge improvement, the SU30MKI that Lao Maozi sold to Ah San, I heard that the tail nozzle needs to be replaced every 50-100 hours, and that is the real ground nightmare." ”

Sitting next to the maintenance area on the spot, Wang Yifu turned his head and said, "Why did you go on a month's vacation this time?" ”

"I went home to see my parents, and then I went to Zhuhai to watch the air show." Xia Yu clapped his hands and sat down as well.

"You're going to the air show?" Wang Yifu was stunned for a moment, and then said: "Since you are planning to go to the air show, why don't you tell me, I have an invitation from a professional group here, and you can enter the cockpit of the plane." ”

"This ......" Xia Yu was stupid, and said with annoyance: "I don't know this, hey, it's a pity." ”

"It's a shame indeed." Wang Yifu said with a smile: "This year's air show, because the results of the No. 9 verification aircraft are so amazing, just to tinker with it, I even ran to the toilet, and next time we have the opportunity to go together." ”

"Well, this one has to be." Xia Yu nodded repeatedly.

Two days later, at 10 a.m., thick clouds blocked the harsh sunlight, and the southeast wind was 2-3, which was a good weather to observe the flight attitude of the aircraft.

Today is the No. 9 verification machine when it has been lifted off again for more than a month, because it is a new engine, so there is no need to do any extreme flight actions, only need to confirm the stability of the engine under normal flight conditions, and some other small improvements, most of which are based on the modifications made by Xia Yu before, so after reading the flight manual, Xia Yu already knows it.

Manipulating 31009 to taxi to the runway take-off position, performing pre-takeoff inspection procedures, afterburner, taxiing, raising head, and lifting, although he didn't fly for more than a month, Xia Yu still had a feeling of nostalgia. The G-force borne by afterburner take-off doesn't have much feeling for Xia Yu now.