Chapter 402 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 significantly 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 the 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 60% of the J-10 in his previous life can still successfully complete its first flight. At this critical moment, some nervousness will inevitably arise.

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

The stability control system designed by Chang Haonan can only prevent 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.

Moreover, the recent floods that broke out in 1997 seemed to mean that the two timelines themselves had 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 night.

After completing the power-on and start-up inspection of the aircraft as usual, the comrades in charge of each system of Project 10 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.

The general preflight preparation meeting literally starts before takeoff, but the situation of the first flight is different after all. The pilot needs to be given enough time, so it has to be held 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. It simply took off, flew around the field for two weeks, and then landed.

You don't even have to retract the landing gear.

Among them, the largest movement range is a steep turn.

But even these seemingly simple and ordinary subjects are still full of uncertainties for an aircraft 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 a plane is similar to driving a car in some ways.

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

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

Take the simplest takeoff as an example. After reaching takeoff speed, the pilot pulls the stick. How long does it take for the aircraft to feel its head rise? 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 takes to the sky.

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

Compared with all previous aircraft projects in China, a major feature of Project 10 is that the test flight team participated in almost the entire design process of the aircraft. Therefore, what Xin Xiaowen said, Lei Qiang, as the chief test pilot, is relatively clear.

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

Only by being serious, meticulous and meticulous can we ensure that nothing goes wrong.

"The J-10 uses the dual logic of force feedback and displacement stroke in the flight control design. This is the first of its kind in the world. There is no mature experience for reference."

After Xin Xiaowen's speech, Yang Wei, who is mainly responsible for flight control design, specifically emphasized:

"Although all test pilots have adapted to the iron bird platform for two years in advance, this dual logic has not yet been restored on the ground. When controlling the joystick, you must pay attention to the strength of your hands and the strength of the pole at the same time. The two will work together to affect the aircraft's response to operations. We need the test pilots to feel the appropriate weight of the current impact of the two on the flight control during the first flight, as well as the specific flight control quality."

Lei Qiang wrote down what Yang Wei said with a red pen, 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, the feel should be similar to borrowing some F27 operating logic based on the Su-16."

Although it was six or seven years ago that this control logic was adopted, he had a detailed understanding of it when he and Yang Wei incorporated the active stability control system into the comprehensive flight control program. At that time, the first 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.

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

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

However, the actual feedback situation is not like this. The control method of force feedback 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 Category or , with only an extremely narrow Category area.

It's a bit like an F1 car, high performance, but difficult to drive. It's a proper equipment for experts.

This also results in the F16's two-seat proportions being far greater than 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-a-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 plane 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 pressure on the test pilots regarding the joystick is indeed relatively high. After all, this is the first aircraft in the world to adopt this kind of control logic."

Perhaps because he felt that the atmosphere at the meeting was a bit heavy, Yang Wei suddenly changed the subject 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 working status of the engine to avoid exceeding safety limits."

After finishing speaking, he turned his attention 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, there are still quite a few people who 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.

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

"That's right, this system uses a specialized algorithm that can monitor some surge precursors that were difficult to detect in the past. Once abnormalities are discovered, it can automatically deal with 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 for greater movement of the throttle lever, and will automatically choose the most efficient method under safety premise..."

"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.

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

When Chang Haonan introduced it, the comrades at the Flight Test Institute listened particularly carefully.

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 risks, countless of their predecessors have died because of 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..."