Chapter 645: Too good performance is sometimes a kind of trouble

According to the requirements before the test flight, in order to prevent the aircraft's distinctive chrysanthemums from being photographed by interested parties as much as possible, the afterburner state should be maintained after takeoff until it climbs to an altitude of more than 3000 meters before leveling off and starting normal test flight subjects.

The first reason for turning on afterburner is to climb faster, and the second reason is to consider that if someone does squat during the climb, the dazzling tail flames will easily overexpose the camera, making it difficult to clearly capture images near the engine.

The thrust-to-weight ratio of the Su-27 when empty and light on fuel exceeds 1. The aircraft that was temporarily pulled out is the latest batch after weight reduction. Therefore, even a two-seat model with slightly less maneuverability can make such an action. It's still flowing smoothly.

In addition, the day was a little cloudy, so in just a few breaths, Chang Haonan and others holding the telescope could no longer see the shadow of the plane.

"Tsk tsk tsk..."

Although they could no longer see anything, except for Chang Haonan, who had been watching for almost a thousand hours at Institute 624, the others still looked unsatisfied and were reluctant to even put down their telescopes.

"This tail flame... is so blue that it turns purple..."

Luo Shida, who was standing on the left hand side of Chang Haonan, was originally a little hunched due to his age and the recent intensity of work, but at this moment, he actually stood up straight:

"I've never seen such a beautiful one before..."

At this point, he finally put down the telescope and turned to look at Chang Haonan next to him:

"The waves behind the Yangtze River push the waves ahead..."

The latter is now basically immune to this type of appreciation. Under normal circumstances, even when the other party is still making preparations, he has already prepared the polite words of routine response just by subconscious.

But Luo Shida did not follow common sense at all:

"I, Lao Luo, have only been retired for a few years, but I had never heard of such a turbofan 10 before the year before the year before last. Comrade Haonan really has a good plan..."

"Wherever, it's not just..."

Chang Haonan was halfway through speaking before he felt something was wrong——

Why does this old comrade feel that his focus is different from others?

But the other party is an elder after all, and Luo Shida is also considered a Taishan Beidou-level figure in the field of aviation manufacturing, so he cannot let the other party stand aside.

So after thinking for a moment, he replied:

"There is no strategy to speak of. The main thing is that the comrades in the project team work together. Otherwise, even if I have a ready-made plan, I won't be able to advance so fast..."

As a result, when Luo Shida heard his answer, he was not in a hurry, but instead smiled mysteriously:

"It doesn't matter, I understand, the string of confidentiality needs to be tightened... You don't need to answer directly..."

"..."

Chang Haonan was completely confused. He almost blurted out and asked the other party what he knew.

But it doesn’t feel right.

The result was that he was completely speechless for a moment.

When Luo Shida on the opposite side saw him being speechless, he confirmed the plot he had just imagined. He stopped talking and just turned back with a mysterious smile and raised the telescope again. , looked at the sky where there were only clouds left, and at the same time actively changed the topic:

"The tail flame of this color...the temperature in front of the turbine is probably not too low..."

In fact, in the years before Chang Haonan was reborn, as the temperature in front of the aircraft engine turbine increased to more than 2000K, engineers no longer believed that there was a strict correlation between the color of the tail flame and the temperature.

However, as the millennium approaches, this perception cannot be said to be problematic.

So he nodded directly:

"Yes, the temperature was still relatively low when we first designed it, but the cooling technology and new coatings developed later were so effective that it increased by more than 200 degrees..."

Chang Haonan's answer made Luo Shida raise his eyebrows. Hearing this, he thought to himself, the Turbofan 10 also encountered an iterative upgrade of active cooling technology during the development process. It will definitely not be completed in less than ten years. My previous guess That's right...

If the latter is allowed to keep thinking like this, there won't necessarily be any outrageous plot.

Fortunately, at this time, Song Shangcai's voice came over the radio:

"Report to the command center that it has reached altitude 6000 and requests to switch the flight mode to 'test' state."

The people standing in front of the window suddenly regained their serious expressions, put down their telescopes, and returned to the radar screen in the command center.

"Received, request approved."

The commander sitting behind the communication terminal replied decisively.

……

At the same time, in the cockpit of aircraft No. 1010, Song Shangcai quickly entered a series of four-digit numbers on the multi-function display, and then pressed "Confirm" to release the flight mode lock restriction——

As He Ming said before, the flight control of this J-11WS has been verified on the J-8IIACT a long time ago. In addition, the turbofan 10 has full digital control capabilities, so it directly integrates flight and thrust at the control level. change.

It can even be regarded as the second flanker in the world with this ability.

Directly on the same starting line as the No. 711 high-mobility verification aircraft at the flight control level.

Compared with traditional flight control systems that control the rudder and power separately, the biggest advantage of integrating flight and thrust is that the movements of the pilot's hands and feet no longer directly control the power and rudder of the aircraft, but directly control the aircraft's Behavior.

For example, the most common action is to push the throttle lever with the left hand.

In previous aircraft, this action actually increased the engine speed, thus pushing the aircraft to increase speed.

However, as to how, how much, and when the rotational speed is increased, it is up to the pilot to make his own judgment.

For a control system that integrates flight and thrust, pushing the throttle lever is only equivalent to giving an acceleration command to the aircraft. The flight control will automatically coordinate the cooperation between the engine thrust and the rudder surface to make the action expected by the pilot. .

This ability is basically useless for normal aircraft in level flight, but for fighter jets that need to perform various extreme maneuvers, it can greatly reduce the pilot's operating pressure.

On this J-11WS, considering that the aircraft still needs to ensure basic safety during takeoff and landing, and the flight test subjects are also completed in the sky, when designing the flight control, the thrust under normal flight conditions was specially considered. Control is handed over to the flight controller.

In other words, the test engine will automatically maintain the same thrust as the other engine as much as possible. At the same time, the six control surfaces of the aircraft will also automatically adjust to try not to let the aircraft go astray.

This is also the reason why Song Shangcai saw the relatively small pointer of the engine tachometer on the left side just before taking off——

When full throttle thrust is greater, to ensure the same thrust as another engine, the speed ratio naturally has to be lowered.

However, the fully electronically controlled turbofan 10 adjusts thrust much faster than the electronically controlled + hydraulic AL31F, so at the moment when the throttle changes, you still have to move the lever slightly to ensure balance.

Now, after turning the flight mode to the 'test' state, these two layers of protection no longer exist.

Both engines will maintain the same throttle opening depending on the position of the throttle valve.

Sure enough, almost the moment Song Shangcai pressed the confirmation button, the seal of the turbofan 10 that had been holding tightly was finally released.

He felt the entire plane lurch sharply to the right, and almost subconsciously stepped on the left rudder, trying to pull the plane back to flying straight forward.

But anyone who has flown an airplane knows that without the involvement of flight control, the impact of power asymmetry cannot be compensated for simply by adjusting the vertical tail action surface.

Therefore, although Song Shangcai had made a lot of preparations before taking off, it was still a bit difficult to control the amount of movement on his feet when he actually started.

Especially when he was changing the throttle while performing preset flight movements, it was so awkward.

It took him three attempts to make a steep turn without losing height.

"Unit 1010, is there a problem?"

The tower commander saw the abnormal track on the radar and asked with some concern.

"Report to the command center. The thrust of the left engine is too great, and the throttle response is much more sensitive than before. I need to get used to it for a while."

Although Song Shangcai is not as experienced as Fu Guoxiang, he is also from a serious test pilot training unit and is confident that he can adjust in a short period of time.

The latter nodded and indicated that he should just listen to the pilot.

Although this flight carried light fuel, thanks to the J-11's inherent large fuel capacity, it was more than enough to complete the test flight. ,

After hearing this answer, the commander looked back at Chang Haonan who was standing behind him, obviously seeking advice.

"Just listen to the pilot."

Chang Haonan put a hand on the other person's shoulder and said in a deep voice:

"The performance of this engine has been greatly improved. It's normal to not get used to it when you first get started, but there won't be any major problems."