We can sometimes see a plane in the air after flying, leaving a long white line in the sky, which is the special cloud system formed by the condensation of water vapor after the hot air discharged by the plane is mixed with the cold air in the sky.

Now the state has increased its investment in environmental protection, and harmless treatment equipment has been installed at the exhaust port of the test bench, so the water vapor discharged from the test run is basically in line with the requirements of environmental protection.

Li Shan also knows a little about these, if the white smoke comes out, it proves that the test is normal, and if the white smoke is mixed with yellow smoke, it means that the fuel may be mixed with lubricating oil, and the fuel and lubricating oil systems are different systems, if the fuel is mixed with lubricating oil, there must be a problem with the internal system of the engine, if it is black smoke, then this situation is on fire.

When Li Shan came to the control room of the test bench, he saw that the room was full of people, these people were talking and laughing, and when he saw Li Shan coming in, he looked at him together, and one of them said: "Why did you come, I have been waiting for you for a long time." ”

This person is Lu Sheng, the leader of the second team of the test section, because Li Shan often comes to the car platform to troubleshoot, so he is also quite familiar with the people here, so he talks very casually.

"Where is the oil leak?" Li Shan asked straight to the point.

"I don't know. The answer was quite crisp.

Seeing Li Shan staring at himself, Lu Sheng smiled slightly and said: "I really don't know, if you don't believe it, you can go down and take a look, as soon as you drive, it's like rain inside, and you really can't see where the oil leak is." ”

"Look at what your engine is equipped with, please, can you use snacks. The other said a little unceremoniously.

Li Shan glanced at this person, he also knew this person, but he couldn't name it, he knew that this person was a mouth that could chatter, so he didn't pay attention to him, turned his head to Lu Sheng and said, "Then take me down to have a look." ”

The test bench is divided into two parts, one part is the control room, which is mainly used to control the engine operation, and the other part is the engine test workshop.

Lu Sheng opened the thick door leading to the test workshop, and then led Li Shan in.

They descended directly to the bottom of the test hall along an iron ladder with a handrail on one side.

The interior of the test hall is large, three stories high, and an engine hangs alone in mid-air.

Due to the loud noise during the engine test, in order to prevent noise leakage, several iron doors and surrounding walls in the test workshop are particularly thickened, and sound-absorbing panels are installed on the entire wall and door, so there is no feeling of emptiness when talking in such a large space.

There was a strong smell of oil vapor in the air, and the light was a little dim. Li Shan frowned, he looked at the engine hanging in the air, and said to Lu Sheng, "I need to go up and have a look." He went straight to the lifting platform below him.

After seeing Li Shan in place, Lu Sheng pressed the switch. With a rumbling sound, the lifting platform slowly rose.

When he saw that the height was about the same, Li Shan shouted to stop, and Lu Sheng pressed the stop button.

Looking up at the dense tubes under the engine, Li Shan had a headache, he turned on the flashlight and checked it carefully.

Oil was dripping everywhere, and I couldn't tell where it was leaking out for a while.

Li Shan took a drop with his fingers, leaned closer to his nose and sniffed, well, this is lubricating oil.

Now it's a problem!

There are many pipes on the engine, including lubricating oil pipes, fuel pipes, air pipes, and cable pipes, and among them, the most lubricating oil pipes.

Even if you know that the oil is leaking, the intricate and intertwined pipes on the engine are sometimes very hidden and difficult to pinpoint.

"Can you drive the car again and let me see where the oil is leaking?" Li Shan said to Lu Sheng.

"No problem, I'm going to go up and drive now, you have to look carefully down there, I'm only driving to the slow train, these are earmuffs, you have to put them on when you drive in a while." Lu Sheng smiled and handed Li Shan something like a headset, which was a necessary protective equipment for those test workers.

Li Shan didn't dare to slack off, and hurriedly put on the earmuffs, and the sound of the outside world could not be heard, as if the whole world was quiet, and there was a feeling of isolation from the outside world.

Through the monitoring window of the control room, seeing Lu Sheng stretching out a thumbs up, Li Shan nodded.

After a while, the engine began to start, and as the engine continued to run, the sound came out louder and louder, and this huge sound passed directly into Li Shan's brain through the earmuffs.

Isn't there something wrong with these earmuffs, there has never been such a situation before.

With doubts in his heart, Li Shan moved his gaze to the bottom of the engine that was running, just as Lu Sheng said, as soon as the engine was running here, oil was dripping everywhere below, a bit like the scene of raindrops dripping on the leaves on a rainy day in summer.

He turned on the flashlight, first checked the place where the oil leaked the most, and then began to search inch by inch along the oil road.

More than ten minutes passed, Li Shan's eyes were a little dazzled, but he still didn't find the fault point, plus the noise of the engine made him feel upset, his head couldn't help but stick closer to the engine, and the dripping oil droplets inevitably fell on his head, and Li Shan couldn't take care of these for a while.

It's really evil today, this noise is a little too loud, and after staying here for a long time, I feel more and more uncomfortable, and I just feel flustered, so let's go out and take a breath first.

When Li Shan returned to the control room, he saw that the group of people inside were looking at him with a smile.

No matter how you look at this smile, it feels like bad intentions! Li Shan can feel his embarrassment, seeing someone saying something to him, but seeing his mouth moving, he can't hear what he is saying.

Zhengjue was strange, and suddenly saw a person pointing to his ear, Li Shan reacted, it turned out that he was still wearing earmuffs on his head, no wonder he couldn't hear what they said.

The moment Li Shan took off the headphones, the sound of the outside world poured into his ears all at once, and the group of people in the room all laughed.

Looking at Li Shan's unexplained expression, Lu Sheng smiled and said, "How is it, the voice inside is pleasant enough, right?"

"What did you say?" Li Shan didn't quite understand, and subconsciously turned his head to look at the computer on the console, and the display screen clearly displayed: "Maximum state".

These kids actually gave me the "maximum state", so angry that Li Shan kicked Lu Sheng, and Lu Sheng dodged sideways with a grin.

The running state of military aero engines is generally divided into: slow state, cruising state, maximum state, and afterburner state.

Slow running refers to the minimum speed at which the engine can maintain stable operation. The slow state is mainly used for the aircraft to warm up after starting, taxiing on the ground, and finally approaching, etc.; the cruising state is used for the aircraft to cruise, land or taxi; the maximum state is used for the aircraft to climb, etc.; and the afterburner state is mainly a state used by the aircraft (generally not used by civil aviation) when pursuing or escaping.

Therefore, the afterburner state is the maximum state when the aero engine is running, and the speed even reaches more than 10,000 revolutions per minute, you can imagine how loud the noise it emits, some people describe it as thunder, although Li Shan has been to the test bench many times to deal with the problem, but he has never encountered the situation of opening the afterburner.

Even so, the rotational speed at maximum is quite high, so the noise generated is very high. And the guys on the platform actually drove the engine to the maximum, no wonder Li Shan couldn't bear it inside.

But fortunately, they drove at the maximum, and it happened to expose the oil leakage of the engine, if the general slow car really couldn't see it, at this time, Li Shan already had a plan in his heart.

He remained silent, deliberately making a very depressed look, and sighed at the same time.

Seeing this, Lu Sheng hurriedly asked, "How is it, have you found the place where the oil leak is?"

"I found it, on the side of the installation of the fuel flow regulator, maybe this accessory is not installed, I went back to the foreman to find a way. Li Shan said expressionlessly.

"Okay, then you can go back and think about it. Lu Sheng looked at Li Shan as if he was sympathetic, but Li Shan saw something different in his expression.