The Military-industrial Scientific Research System of the Academic Master Chapter 402

Chapter 402: The Test Pilot's “Amulet”

 In fact, this is the first time that Chang Haonan has truly participated in the preparations for the first flight of a “new aircraft”.

Compared with the J-8C, which has been greatly modified based on the old model, and the J-H-7 or H-6 AIT, which have simply undergone limited equipment upgrades, the aerodynamic design, flight control design and various flight-related cores of the J-10 Parts are almost all new.

Although some technologies related to electronic equipment and production processes have been verified on the J-8C, overall, the proportion of new technologies applied in prototype No. 1001 at this time still exceeds 40%.

 Under normal circumstances, this is a number that is enough to stop a person's heart and lungs.

Not to mention the parties involved such as Xue Chishou or Song Wencong, even if Chang Haonan lives again, he knows very well that the J-10 with a figure of up to 60% in his previous life can still successfully complete its first flight. At this critical moment, some nervousness will still arise.

 There is no other way, rationality is rationality, and emotion is emotion.

The stability control system designed by Chang Haonan can only avoid engine failure due to intake distortion, but accidents are not foreseeable by humans at all.

This actually raises another question, that is, as he affects more and more of the timeline of this life, there will be more and more things that are difficult to predict like when he was just reborn.

Furthermore, the recent floods that broke out early in 1997 also seem to mean that the two timelines themselves have some slight differences in some random factors.

If the multi-game randomness is a game setting, it will naturally improve the playability to a great extent. However, in reality, it is not easy to get a chance to cheat in a multi-game life. As a result, many things are different from the previous life. Same, but not as interesting.

 That evening.

 After completing the power-on inspection of the aircraft as usual, the comrades in charge of each system of the No. 10 Project and the relevant personnel of the China Flight Test Institute who were about to participate in the test flight gathered together to hold a pre-flight preparation meeting.

 General preflight preparation meetings are held literally before takeoff, but the situation of the first flight is different after all. Sufficient time must be left for the pilot, so it has to be carried out in advance.

Chang Haonan attended as "one of the important designers of the flight control system".

“Comrades, let me first clarify to you the entire process of the test flight tomorrow morning.”

 Xin Xiaowen, chief flight test engineer of Project 10, tapped the table with a pen and began to speak first.

As a brand new key model, the J-10's original first flight was relatively conservative, with the J-10 simply taking off, flying around the field for two weeks, and then landing.

 There's no need to even retract the landing gear.

 The largest movement range is a steep turn.

 But even these seemingly simple and ordinary subjects are still full of uncertainties for a plane that has never flown into the sky before.

Prior to this, aircraft No. 1001 had conducted several high-speed ground taxiing tests. Chief test pilot Lei Qiang even completed a brief lift-off lasting a few seconds during the wheel-raising test, proving that the aircraft was not advanced in basic design. There is no problem.

  In other words, it is definitely possible to take off.

But the problem is that neither the iron bird platform (a comprehensive test bench for the flight control hydraulic system, equivalent to a simulator) nor the ground taxiing can simulate the true response characteristics of an aircraft.

 Flying an airplane is somewhat similar to driving a car in some ways.

For example, there is an "operating feel" that is difficult to quantify, mysterious and mysterious but does exist.

Each model of aircraft has its own distinctive personality and characteristics.

Taking the simplest take-off as an example, after reaching the take-off speed, the pilot pulls the stick, how long does it take for the aircraft to feel its head rising? How much force and speed do you pull and what will happen to your head speed? At what angle will the plane stop when it raises its head? How responsive is the engine after pushing the throttle lever? At what rate should the throttle be controlled to achieve a balance between maintaining stable operation of the engine and flexibly adjusting the power level of the aircraft...

These are things that can only be felt one by one when a real airplane flies into the sky.

 These simple subjects set up in the first flight are largely to test this feel and pave the way for more complex test flights in the future.

  One of the major features of Project 10 compared to all previous aircraft projects in China is that the test flight team participated in almost the entire design process of the aircraft. Therefore, Lei Qiang, the chief test pilot, is relatively clear about what Xin Xiaowen said.

Despite this, he still kept his head down and took notes meticulously.

 Being serious, meticulous and meticulous can ensure nothing goes wrong.

“The J-10 adopts the dual logic of force feedback and displacement stroke in the flight control design. This is a first in the world, and there is no mature experience for reference.”

After Xin Xiaowen's speech, Yang Wei, who is mainly responsible for flight control design, emphasized: “Although all test pilots have adapted to the iron bird platform for two years in advance, this dual logic has not yet been implemented on the ground. To restore it, when controlling the joystick, you must pay attention to the strength of the hand and the stroke of the joystick at the same time. The two will work together to affect the response of the aircraft to the operation. We need the test pilots to feel the current situation during the first flight. Whether the weight of the impact of the two on flight control is appropriate, and the specific flight control quality.”

Lei Qiang wrote down what Yang Wei said with a red pen, and then raised his head:

“I understand, I will pay more attention to this aspect tomorrow.”

At this time, Chang Haonan, who had been silent just now, also added:

“If I have to describe it, this feel should be similar to borrowing some F16 operating logic based on the Su-27.”

Although it was six or seven years ago that this control logic was adopted, he had learned about it when he and Yang Wei incorporated the active stability control system into the comprehensive flight control program. That's how it feels.

Of course, there is another level of reason for adopting this statement -

Lei Qiang may be the only pilot in the world in this era who has flown both the F16 and Su-27, two typical fly-by-wire fighter jets.

 So when he heard what Chang Haonan said, he nodded lightly and understood almost immediately.

  F16 adopts a quite radical side-lever position afterburner feedback control logic in the cockpit design, which can theoretically greatly improve the pilot's convenience in controlling the aircraft.

However, the actual feedback situation is not like this. The force feedback control method is too anti-human and almost completely offsets the control advantage brought by the side stick design.

Although the flight performance of the F16 itself is quite superior, the "user experience" it brings to pilots is very average. The flight quality under most envelopes is in the second and third categories, with only an extremely narrow first category area.

  Somewhat similar to an F1 racing car, it has high performance but is difficult to drive. It is a proper equipment for experts.

 This also results in the F16's proportion of two-seat models being far greater than that of almost any other aircraft.

 The J-10 has learned this lesson in its control logic and chose to combine force feedback and displacement stroke feedback.

In fact, all subsequent third-and-half-generation and fourth-generation fighter jets have adopted similar strategies. This may be the first time that the Chinese aviation industry, which was still very weak at the time, has led the trend in some aspects.

However, as "the first airplane to try something new", naturally there is no previous experience for reference.

 We can only let Lei Qiang go up and explore by himself.

“The joystick put a lot of pressure on the test pilots. After all, this is the first aircraft in the world to use this kind of control logic.”

Perhaps feeling that the atmosphere at the meeting was a bit heavy, Yang Wei suddenly changed the topic and adopted a more relaxed tone:

"But there is also good news. Thanks to our latest version of the flight control update, the operation of the throttle lever has become much simpler than in the past. Although the engine is not produced by us after all, we cannot achieve full digital control with complete functions, but Under some extreme working conditions, the flight control system can automatically control the operating status of the engine to avoid exceeding safety limits. "

 After finishing speaking, he turned his eyes to Chang Haonan next to him, indicating that the latter could introduce it in detail.

Although it has played an important role in the ground testing process, as a function that was only recently added to the J-10 flight control, quite a few people still lack a comprehensive understanding of it.

 For ordinary users, there is no need to insist on knowing the reason, but since it is a test flight, there is no harm in knowing more.

 Furthermore, it can also improve the test pilot's confidence in the aircraft.

“That's right, this system uses a specialized algorithm that can detect some surge precursors that were difficult to detect in the past. After detecting abnormalities, it can automatically handle them and inform the pilots in the cockpit of potential risks..."

Chang Haonan introduced the basic principles, working logic and applicable situations of the active stability control system in about half an hour in the shortest possible language:

“This system can help pilots avoid worrying about engine stability, allow more extensive adjustments to the throttle lever, and will automatically select the most efficient method under safety conditions...”

“The pilot just pushes the throttle, and the flight control does the rest!”

Chang Haonan borrowed an advertising slogan that did not exist in this era and said it in a slightly joking tone.

 The atmosphere in the venue finally became more lively.

 Actually, his set of things is a bit like the airplane version of quattro.

 Comrades from the Flight Test Institute listened especially carefully when Chang Haonan introduced it.

Especially when he said that he could predict potential risks in advance and automatically reduce the speed to avoid them, many people had complicated expressions on their faces.

 As the test flight unit that bears the greatest risk, countless of their predecessors have died due to surge, the biggest enemy of flight safety.

 If such a set of things had been available before, many accidents would have been avoided.

“Comrade Chang Haonan, this is an amulet for our test pilot...”

 (End of this chapter)

Chapter end