Chapter 645: Too good performance is sometimes a kind of distress
According to the requirements before the test flight, in order to prevent the distinctive chrysanthemums of this aircraft from being photographed by interested parties, the afterburner state should be maintained after takeoff. It was not until the aircraft climbed to an altitude of over 3,000 meters that it leveled off and began the normal test flight.
The first reason for turning on afterburner is to climb faster, and the second reason is to consider that if someone really squats during the climb, the dazzling tail flame 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, so even a two-seat model with slightly less maneuverability , making such an action is still smooth and smooth.
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 in 624, the other people still looked unfinished, and they didn't even have a telescope. Be willing to let it go.
"This tail flame... is so blue that it turns purple..."
Luo Shida, standing on the left hand side of Chang Haonan, was originally a bit hunched due to his old age and the recent intensity of work. , but at this moment, he actually stood up straight:
“I have 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 now appreciates this type of He is basically immune. Under normal circumstances, even when the other party is still preparing the 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, Luo, have only been retired for a few years, but I had never heard of such a turbofan before the year before last. 10. Comrade Haonan really has a good plan..."
"Nowhere, not just..."
Chang Haonan was halfway through speaking before he felt something was wrong——
Why does this old comrade's focus seem to be different from Are others different?
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 while, I still answered:
"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, Luo Shida heard his answer. Not only was he not in a hurry, but he showed a mysterious smile:
"It doesn't matter, I understand, the string of confidentiality must 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 I was completely speechless for a while.
Seeing him speechless, Luo Shida on the other side confirmed the plot he had just imagined. He stopped talking and just turned back with a mysterious smile. Go, raise the telescope again, look at the sky where there are only clouds left, and at the same time actively change the topic:
"The tail flame of this color... I'm afraid the temperature in front of the turbine is not low..."
In fact, in the years before Chang Haonan was reborn, as the temperature in front of the aircraft 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 we approach the new millennium, 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 coating developed later were very effective. It was raised by more than 200 degrees again..."
Chang Haonan's answer made Luo Shida raise his eyebrows, wondering what this means. The turbofan 10 also encountered an active cooling during the development process. The iterative upgrade of technology will definitely not be completed in less than ten years. My previous guess was indeed correct...
If the latter continues to think 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 we have reached an altitude of 6000 and request to switch the flight mode to the 'test' state."
Standing in front of the window The people who were watching suddenly became serious again, put down their telescopes, and returned to the radar screen in the command center.
"Received, approve the request."
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 capability, so it is directly controlled by the aircraft. At the same level, the integration of flying push has been achieved.
It can even be regarded as the second flanker in the world with this ability.
On the flight control level, we stand on the same starting line as the No. 711 high-mobility verification aircraft.
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 your left hand.
In past airplanes, this action actually increased the engine speed, thus pushing the airplane 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 achieve Execute the actions 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, so when designing the flight control, the Thrust control under normal flight conditions is left 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 that the tachometer pointer on the left side of the engine was relatively small just before taking off -
When the full throttle thrust is greater, it is necessary to ensure that it is in contact with the other engine. The thrust is the same, so the speed ratio will naturally be lower.
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 changing the flight mode to the 'test' state, these two layers of protection no longer exist.
Both engines will maintain the same throttle opening according to the position of the throttle valve.
Sure enough, almost at the moment when 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.
So, even though Song Shangcai had made a lot of preparations before taking off, it was still a little difficult to control the amount of movement on his feet when he started.
Especially when he was changing the throttle while doing the 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 that the thrust of the left engine is too great and the throttle response is much more sensitive than before. I need to adapt for a while.”
Although Song Shangcai is not as experienced as Fu Guoxiang, but He is also from a serious test pilot training unit, so he is confident that he can adjust in a short period of time.
The latter nodded and indicated that just listen to the pilot.
Although this flight carried light fuel, thanks to the large fuel capacity of the J-11, 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 improved too much. It’s normal to get used to it, but it won’t cause any major problems.”
(End of this chapter)