"Qin Feng, your skills are very skilled." After Wang Yang came down, Qin Feng had already started to rotate around the J-8, looking at the engine in the back, and then looking at the air intake in front.

Hearing Wang Yang's words, Qin Feng couldn't help but wonder: "Skilled? ”

"Yes, you dropped from 12,000 meters to 1,000 and 5,000 meters, and you actually completed six air restarts in between! I had the same accident last year, and in the same amount of time, I only restarted three times. ”

At the same altitude, if it is level flight, the time is about the same, if it is a dive, it must be short, in short, last year, Wang Yang restarted three times, and it reached an altitude of 1,500 meters, Qin Feng actually carried out six times in a row, and his hands and feet were absolutely numb.

"Our plane, it's easy to park in the air, huh?" Qin Feng frowned.

Engine air parking causes the aircraft to lose or partially lose power, posing a serious threat to flight safety, so the less air parking the better, generally speaking, the initial engine can do 1 time every 1000 flight hours, after which the advanced engine will be reduced to about once every 106 h.

However, aviation gas turbine engine is a product with harsh working conditions and complex structure, and it is still difficult to avoid air shutdown due to design, process, use and maintenance, working conditions, etc.

Even so, it's too strange for your own air to stop, right?

"yes, I was testing the flight envelope in the subsonic range, and it was just a side turn, and it stopped in the air." Wang Yang said: "It was really an evil sect at that time! ”

Just one side turn, and it stopped in the air? Qin Feng thought of his flight action this time, and suddenly he was full of suspicions, the problem of the engine?

This seems to be a bit unreasonable, after all, on the J-7, the turbojet-7 engine is used very well! What's wrong now?

If not the engine, then what?

Qin Feng's eyes looked at the engine behind, slowly, slowly, turned to the front, looking at the huge air intake, if it wasn't the problem of the engine, it was a problem in the case of climbing and side turning, then there was only one possibility!

Intake tract!

Compared with others, one of Qin Feng's biggest advantages is that he reads a lot, in foreign countries, when designing an aircraft, the air intake and the engine must be matched, and one of the biggest disadvantages of the nose air intake is that it is not easy to match!

Why is it not easy to match?

Because the air intake is long, from the nose to the back, in this way, the airflow has to pass such a long distance, and if there is any change in the middle, it may be stuck.

So, why doesn't this kind of problem occur frequently on the J-7?

On the one hand, the fuselage of the J-7 is not so long, on the other hand, the J-8 is twin-engine!

When Qin Feng thought of this, his brows furrowed even tighter, and he slowly walked towards the back, Wang Yang couldn't help but shout, "Hey, where are you going?" ”

Qin Feng's performance today is a little strange, didn't he go to the analysis room to look at those complicated data?

Qin Feng is going in the wrong direction.

"I'm going to look up some information." Qin Feng said, "Go to our data room." ”

Now, Wang Yang followed Qin Feng and walked to the data room of the test flight institute, facing the data manager, Qin Feng said: "Please find me the information of the J-6, about the engine parking in the air." ”

J-6? This kind of aircraft is already an outdated model, although it is still in production, it is already an old model, why did Qin Feng come here to find information on this kind of aircraft?

It doesn't match the J-8 either.

Hearing Qin Feng's words, the data administrator said, "There is a lot of information here." After all, our J-6 was the main force in previous years. ”

The situation in previous years, everyone naturally knows, what other factories pay attention to quality? That's an absolute problem.

J-6 fighter, supporting the use of turbojet-6 engine, which is based on the Soviet-made Pд-9Б jet engine imitation and development of a series of models, finalized in July 1959, is China's first supersonic aero engine, in addition to the J-6 fighter, there is also a strong -5 strong strike aircraft.

The turbojet-6 series engine is the largest number of aero engines produced in China, with a total output of 29,316 units, and the actual batch production began in 1961.

It was precisely this special era, so the quality problem of the turbojet-6 engine ran through the sixties and seventies, causing a large number of flight accidents, which were not completely solved until the early eighties.

For example, the original quality was not good, and as a result, the technical structure of the engine was modified without authorization, and the shaft head was reduced, resulting in a large number of engine failures and accidents.

At the same time, it is constantly improving, and from 1964 to 1983 after four batches of improvements, the performance has been greatly improved. It was not until the fourth batch of improved models in 1983 that they entered the quality maturity period, but at this time, it was already on the verge of elimination.

Speaking of the accident of this plane's air stop, it is even more numerous, the data administrator said while confirming that Qin Feng really wanted to see it, signed, and then pulled out a thick stack.

Confidentiality stipulates that they can only see it here, and they cannot bring the information back.

So, sitting on the small table next to him, Qin Feng slowly flipped up.

I don't look at the air parking due to quality problems, but I want to see the air parking caused by maneuvers.

Wang Yang flipped along the side, and time passed slowly.

Half an hour later, Qin Feng finally found the first one.

In '64, when a pilot in a certain department of the Air Force was doing training, he pulled the rod, turned sideways to climb, suddenly stopped the engine, and finally parachuted.

There is a detailed accident report inside, and there is a line of analysis underneath.

When turning sideways, the airflow in the intake tract is distorted, causing the engine to stall!

Moreover, it was both engines that stalled at the same time.

Why?

The same nose air intake layout, there is no barrier inside, the two engines share the air intake, so that once the air intake is insufficient, it will cause no one to have enough air for the two engines, and finally both engines stop!

The J-6 and J-8 are the same in that they are both twin-engine fighters, both have nose air intake, and at the same time, the air intake tract is not separated!

If there is a partition in the middle of the air intake, each going its own way, then at most one is going out, and now the air is not enough, everyone is grabbing, so it is necessary to turn off the fire, and both will go out!

There must be a reason for the J-8's ignition in the air, but the specific reason still needs to be known through detailed analysis of the data.

Qin Feng didn't leave immediately, but continued to search, and after another half an hour, he found it again, exactly the same.