The military-industrial scientific research system of the academic master

Chapter 78 J-8-3, its second first flight!

Yang Fenghata and others are not the only ones paying attention to this test flight.

In another assembly workshop of Factory 112, technicians Artyom Trusov and Alexander Mosin from the Sukhoi Design Bureau are assisting their Chinese counterparts in the final preparation of the J-8II ACT stabilization verification machine before leaving the factory. verify.

While resting near the door of the factory building, they naturally witnessed the entire process of the sliding test.

The aircraft test flight itself is actually nothing worth keeping secret.

The main reason is that the aircraft is so big and the turbojet engine is so noisy that there is really nothing that can be concealed.

Not to mention the people who work in Factory 112, even ordinary people living around can see them casually.

The real secret is the detailed data obtained from the test flights.

In fact, the fact that these two Sukhoi engineers were able to take a break at exactly this time, and to rest for several hours at a time, was simply specially arranged by Yang Fenghata.

Not only are there morning sessions, there will even be afternoon sessions later——

What we want is for them to see the first flight of prototype No. 04!

…

At noon that day, Tu-154M landed at Taoxian International Airport, and Chang Haonan got on the familiar 212 Jeep again.

Only this time, the car did not go to No. 601, but directly sent him to Beiling Airport.

Then Chang Haonan, who had not yet recovered, saw the No. 04 prototype waiting on the tarmac in the distance, and he was so shocked that he almost exploded.

"I c...Detian, have you already changed it?"

You must know that prototype production is different from entering the mass production stage. Because the production has not yet been finalized, the efficiency is generally much lower.

It can be seen that 601 Institute and 112 Factory are definitely fighting for their lives for this matter.

"During this period, all the departments in the institute have not turned off the lights."

Yao Mengna, wearing a blue overalls, stood at the door of the jeep and said that her long hair was hidden in a hat probably because she went to the workshop.

"Come with me, the first flight ceremony is waiting for you." Yang Fenghata directly opened the co-pilot's door and sat on it: "This is your wing. You should witness its first takeoff with your own eyes."

As for the accidental lift off the ground in the morning, the latter was certainly not prepared to talk about it.

Chang Haonan's original intention of coming back early was to verify whether there were any problems with the design of the turbojet 14, but after all, he was not willing to miss the first flight of the new J-8-3.

Yao Mengna also got into the back seat on the other side, and the jeep sped towards the tower.

When passing near the No. 04 prototype, Chang Haonan signaled the driver to slow down and specifically stuck his head out to pay attention to its wings.

He wants to keep this shape in his mind——

This is the first project he has actually designed after his rebirth.

In the past, whether it was the J-7F or the MA-60, although he played an important and even core role in both, he still could not be called "in charge of the design."

But this new wing can.

Twenty minutes later, everything was ready and the real first flight was about to begin.

The test pilot was of course Fu Guoxiang.

Under his control, the aircraft taxied to the ready-to-fly position at the end of the runway with ease.

With this morning's experience, he has basically figured out the taxiing and takeoff performance of this aircraft.

Therefore, after receiving the takeoff order, Fu Guoxiang did not choose a conservative long-distance taxi as usual for the model's first flight. Instead, he directly pushed the throttle valve to maintain the engine speed at a higher level than in the morning.

A faint orange-red high-temperature gas gradually appeared at the tail nozzles of the two turbojet 14 engines, and the air behind the aircraft also experienced optical distortion due to the sudden increase in temperature.

After confirming that the rotational speed was stable, Fu Guoxiang released the brakes. The aircraft instantly lowered its nose slightly and began to accelerate and glide on the runway.

After a taxiing distance of about 500 meters, the No. 04 prototype lifted directly up with a light gesture almost directly in front of the tower, straight into the sky!

"This distance..."

Yang Fenghao, who was in the highest row of the tower, stretched out his palms flat on his forehead to block the sun. Although his telescope was in the hands of Chang Haonan next to him, he could still clearly see the rolling distance used for this test flight. It was much shorter than the one in the morning.

"About 600 meters?" Chang Haonan temporarily put down the telescope in his hand.

"It's almost the same. It's shortened by more than 10% compared to before the improvement." Yang Fenghata was still a little excited in his heart:

"We discovered during the wind tunnel test that the shape of the trailing edge of your slats should be optimized, and the resistance it brings when starting is very small. Now it seems that the actual situation should be even better than the wind tunnel results. .”

This time Chang Haonan just smiled and did not answer.

In fact, in the total design cycle of about 20 days, he spent almost half of the time optimizing this part.

The biggest problem of leading edge slats compared to leading edge flaps is that the induced drag during startup is relatively large.

It would be fine if this aircraft had great flying capabilities, but the thrust of the turbojet 14 is not good at low altitude and low speed, so the drag should be reduced as much as possible.

At the same time, Fu Guoxiang, who was preparing to fly around the field in the cockpit, had also discovered the huge difference between this improved aircraft and the previous one.

From the earliest J-8 Bai to the J-8-2 with air intake on both sides to the current J-8-3, he has flown almost every improved model of the J-8.

But each of the previous ones will become very difficult to control when the speed drops below 400km/h.

In fact, the lift coefficient and available angle of attack of the aircraft are not ideal.

If you push the stick a little, it will drop due to insufficient lift. If you pull the stick, it will cause the angle of attack to be too large and enter a more dangerous stall or even spin state.

There is only an extremely narrow operating range that can maintain the aircraft in controllable level flight.

If there is another interference from outside air flow...

Then this interval is likely to disappear directly.

Therefore, in the past, after flying an airplane to take off, the speed of the airplane would be increased to at least 450km/h as soon as possible to reduce the risk of maneuvering the airplane.

But today the feeling is completely different.

After takeoff, at speeds of 350-400km/h, the aircraft's control efficiency and flexibility far exceeded his expectations. The stick movements he was accustomed to before almost frightened him, who had experienced many battles.

Fu Guoxiang can feel very clearly that 350km/h is definitely not the limit of this aircraft.

According to general custom, the first flight of an aircraft model usually does not even retract the landing gear, and the flight time is basically about 15-20 minutes.

However, the situation of No. 04 is different after all. In addition to flying around and passing through the field, this test flight was also arranged to conduct several tasks to test the available overload under different angles of attack.

It is clear that the R\u0026D team has great confidence in the aircraft.

Therefore, Fu Guoxiang finally decided to request a lower speed pass from the test flight station.

After a few seconds of silence, a reply came over the radio.

"Requesting approval, but the speed of passing the venue shall not be less than 285km/h."