Chapter 598: We don’t have the strength to fly big bricks?

As the test flight and transportation site of Shengfei Group, Beiling Airport is not large in size. After all, there is no daily take-off and landing pressure here.

Therefore, within a few minutes, aircraft No. 1401 had stopped at the end of the takeoff runway, and the wings were readjusted to a 20° sweep angle, which was more conducive to takeoff.

"The area has been cleared. Unit 1401 can take off."

Fu Guoxiang put on an oxygen mask, maintained the brake state and slowly pushed the throttle valve, and watched as the engine tachometer pointer, which had been replaced by a Chinese style, slowly turned to the right.

As a test pilot stationed at Field 112, this is his first time coming into contact with the turbofan 9A model.

In fact, there are currently only three aircraft in the entire China - the 7 and 01 prototypes of the JH-02A, and this aircraft No. 1401, which only uses the turbofan 9A.

However, the steady increase in speed still brings considerable confidence.

It even reminded him of the test flight of the J-8C after major changes two years ago.

They are also two engines installed for the first time, and they also have such a stable speed.

After the engine reached takeoff thrust and stabilized for a few seconds, Fu Guoxiang released the brakes and the plane began to roar and accelerate on the runway.

Fu Guoxiang himself was a little surprised by the pushing feeling coming from behind him.

In his opinion, such an aircraft, which still has an empty weight of about 17.5 tons even after weight reduction, seems to be relatively clumsy.

Compared with the J-11 he had flown before, the F14's greater weight and drag made the acceleration capabilities of this model less optimistic and held it back slightly. However, the excellent lift coefficient still allowed this aircraft to use only Take-off conditions are reached at about one-tenth of the runway, which is about 350 meters away.

After all, the F14 is a relatively mature design. After all, the "first flight" after modification is not exactly the same as the real first flight. The setting of flight subjects is much more open.

After pulling up the plane, Fu Guoxiang retracted the landing gear, then allowed the plane to accumulate some speed, and then made his customary high-angle climb.

Almost at the same time as the throttle valve was pushed to the end, the two engines sprayed light blue tail flames with Mach rings downward in mid-air. The wings also adjusted to a higher resistance in less than 7 seconds. Low sweep angle state of 68° which is more suitable for acceleration.

The two new engines, which are quite powerful at low altitude and low speed, provide Fu Guoxiang with quite confident climbing capabilities. At least in his opinion, there is almost no loss of speed during the current climbing process of close to 70°.

Increasing the sweep angle greatly reduces the lift coefficient provided by the wing, but...

Vigorously miracle.

On the other side, this slightly wild action also caused a burst of exclamation in the command center of the tower.

Of course it was from a representative of the Persian Air Force.

Since there has been no formal means of importing spare parts for more than 20 years, in order to save the life of the machine, they rarely engage in such "wild" driving.

And, on the other hand, if the TF30 engine in the past dared to carry out such large-scale and violent maneuvers at low altitude, % of them would have entered a surge state...

"The climb rate shown this time is obviously higher than in the past..."

A colonel standing next to the leading Persian general stared at it for a while, and then estimated.

"of course."

He Ming already knew the performance of this aircraft, so he did not focus on the aircraft outside. After hearing the Persian's evaluation, he immediately explained:

"We replaced the materials of the skin parts that do not involve the main load-bearing structure, reducing the empty weight by about 700kg. Moreover, the sea-level thrust of the replaced turbofan 9A engine has increased by more than 17% compared with the past."

"By doing this again and again, the thrust-to-weight ratio of the entire aircraft near takeoff can be increased by almost one-fifth, and the power performance is naturally completely different."

When he said this, He Ming even had a confused feeling——

The principle of making bricks fly with great strength can actually be explained from my own mouth one day.

It's amazing.

"in addition."

He Ming's tone suddenly sounded like he was holding back a smile:

"I can assure you that the aircraft had been filled with a standard amount of fuel before the test flight, and there was absolutely no situation where the engine was turned on in advance to consume fuel, thereby reducing the take-off weight."

Hearing this sentence, even the Persian general laughed directly:

"Well, we have been watching just now. You really didn't do any tricks in this regard..."

The two were talking about what happened when Persia purchased US military fighter jets.

The candidates at that time were Grumman's F14 and McDonnell Douglas' F15.

Originally, the flight performance of the latter should be much better, but Grumman specifically asked McDonnell Douglas to perform the performance first, while its F14 kept running its engine on the ground to consume fuel, thus making up for the thrust-to-weight ratio to a certain extent. disadvantages.

Although the authenticity is virtually impossible to test, this story has become one of the famous urban legends in the field of international arms sales.

After the brief joke, He Ming quickly returned to the topic:

"Getting back to the subject, in addition to the superior thrust at sea level, we adopted blade separation flow active control technology in the design process of the turbofan 9A engine, which can cope with very extreme intake distortion."

"Although the specific flight envelope data still needs to wait for our test pilots to fly out the results, from a qualitative point of view, the improved F14 can allow pilots to perform violent maneuvers that were unimaginable in the past, such as... you can't do it anyway. Already seen it.”

The F14A purchased by Persia is an earlier batch of technical versions. The sea-level afterburning thrust of the engine is only 8530kgf. However, the turbofan 10A after some technical improvements of the turbofan 9 has this data above 10000kgf.

"Looking at it this way, the improved F14IC model can probably be equivalent to the level of the US military's F14D?"

Obviously, the Persian Air Force has always been concerned about the improvement of the Tomcats on the US military side.

"You can say that."

He Ming nodded after hesitating for a moment:

"Although the sea-level thrust of the turbofan 9A is smaller than that of the F14GE110 replaced by the F400D, the overall improvement ideas and the performance orientation of the improved model are similar."

Speaking of this, he suddenly remembered an interesting thing:

“说起来，F110GE400和涡扇9A，这两台发动机的总压比恰好都是30.7，比TF30发动机要高出50%。”

"Of course, as a price, the high-speed performance and maximum flight speed of the F14 after the replacement, whether our F14IC or the US military's F14D, are actually reduced."

"Oh?"

The Persian general, who had been holding a telescope, was also attracted by this topic about engines:

"Did you consider benchmarking against the F110 when designing?"

In fact, the reason why they decided to hand over the F14 to China for modification was partly because the size, weight and performance of the 1493 radar could perfectly replace the AWG9, and the other half was because they discovered the turbofan when visiting the Haofei Group. The performance of the 9A engine is quite good.

"That's not it."

He Ming shook his head:

"This is a complete coincidence. In fact, the turbofan 9A is a by-product created by one of our chief designers for technical verification. It is impossible to bother to benchmark other models in terms of total pressure ratio."

This answer was originally just that he told the truth without any deep meaning, but the effect was surprisingly good.

"Wait, you mean, the by-product... already has such good performance?"

Now that No. 1401 had flown far away, it was impossible to see it even with a telescope, so the Persian general simply put it aside, turned around and asked with a shocked face.

He Mingxin on the opposite side said that it was because you didn’t know what kind of hard work Mr. Chang was preparing to do on the Turbofan 10, but the contents of the third-generation (actually 3.75-generation) turbofan engine were all confidential, so he had to change to a more traditional one. Answer:

"Although it is a by-product, the technologies used on it are the latest cutting-edge technologies from the 90s and even into the next century."

"It can be said that although the turbofan 9A was born out of the British Spey, it has no direct relationship with Spey now..."