The weather at Lake Horizontal, the clouds are light and the wind is light, and the sunset is warm.

Yourou led Tao Feiyan and went to Yiqingju to see how the decoration effect was, the interior was still in the finishing stage, and the furniture and paintings had not yet been arranged.

After two or three days, the furniture is in place and you can move in.

Su Jinglu and Han Feng came to the side of the code name Raptor together.

"Brother Feng, these days, Codename Raptor has done some unconventional tests, under extreme weather conditions, the test results are very good, and there is one last test, or you go up with me and finish the test......"

Han Feng's eyes lit up, and he asked with a smile: "What kind of test, you have to pull me along, codenamed Raptor This high-end product, I don't know much about ......"

"It's high-altitude flight, flying up to 10,000 meters in the air and entering the stratosphere. ”

"Fly so high......"

Su Jinglu nodded: "10,000 meters in the air, the requirements for the drive device codenamed Raptor are extremely high, Brother Feng, your wind perception is extraordinary, you can just help me sense it, the wind effect is ......."

Driven by wind element stone, the turbine blade speed is extremely high, and the wind frequency is very fast.

"Okay, flying up to 10,000 meters in the air, you can just overlook the entire Heavenly Realm Lake, and even the Empty Valley Dojo......" Han Feng smiled and couldn't wait, wanting to be in the sky and overlook the rivers, seas and rivers.

Codenamed Raptor, the seven-seater elongated body has a smoother streamline and longer flanks.

The top is added to provide upward power, and the tail wheel is used for direction adjustment, and the humanized porthole design greatly improves the light effect of the riding space.

The two of them climbed the ladder and walked in.

The passenger space and the driving space are set separately, and the scale of the passenger space is much more spacious than the previous generation.

On the seat, the leather seats with high comfort are added, and the fine snow mountain grizzly bear leather is soft and elastic, hand-sewn, and the stitching lines are clear and neat. Under the seat, there is a balance bar that adjusts the angle of the backrest.

In this way, it will be more comfortable to take a nap and take a nap during a long journey, and the backrest will be lowered and lowered.

The entire interior space, the main color of light gray, is low-key and luxurious, mild, and slightly textured.

"Su Jinglu, if you can make a few more codenamed birds of prey, let me know, I'm in the Empty Valley Dojo, going back and forth between Tianjing Lake and Thousand Curtain Cliff, with it, it's very convenient to act. "The cold wind was a little suspicious, and the code name Raptor flew around the Hollow Valley Dojo, too ostentatious.

"Uh-huh, I'm planning this, too. Xiao Su nodded and smiled happily: "It's just that the stone is a little troublesome, and it's not easy to collect......"

"I have time to go to the trading market of Qianmu Cliff and try my luck to see if there are any good stone materials......"

"Well, maybe you're lucky enough to get some ......" Xiao Su nodded lightly, made a look, and said: "Ready to take off, Brother Feng is sitting firm, the code name Raptor take-off stage, there are still some bumps......"

Immediately manipulated the control stick, first adjusted the position of the code name Raptor, and slowly glided on the infinite expanse of the ice of the Heavenly Lake, facing the sunset in the west.

The Codename Raptor glides faster and faster, and after a few seconds, it takes off into the air.

Call!

Call!

Flying rapidly, a roar was deafening, alarming the wild ducks in the reeds, and poured out of the nest.

Codenamed Raptor hovers in mid-air, straight into the clouds.

Beyond the porthole, the huge Tianjing Lake, infinitely vast, shines brightly under the sunset sun, and is magnificent.

Sou!

The wind wheel on the flank, the speed increased again, and the running speed of the top wind wheel also reached the limit, the code name Raptor rose at full speed, pulled up vertically, and in an instant, the flight altitude surpassed the nearest Fanjing Mountain.

Su Jinglu was engrossed, controlling the wind wheel at the tail to adjust the direction and rhythm of flight.

"What is the clearance height now, it feels very high, and outside the porthole, you can see the Guyue Peak over there in the City of Wind. The cold wind was a little nervous, and this was the first time he had seen the Mogao area, the top of Guyue Peak.

"I just flew at an altitude of 3,000 meters, and I am 10,000 meters away, and it will be a while. Su Jinglu looked at the scale on the display instrument and replied.

Han Feng leaned his face against the porthole and glanced down, and Fanjing Mountain on the shore of Tianjing Lake became slightly insignificant.

His heartbeat continued to increase with the flight altitude, beating faster, a little afraid of heights, he closed his eyes directly, his nerves were tense, and he regretted it a little in his heart, and promised Xiao Su to take a 10,000-meter flight test together.

Su Jinglu has rich flying experience, and his psychological quality is better, his face is calm, he is not alarmed, he controls the control stick steadily, and steadily increases the altitude of the flight ground.

Through the clouds, his eyes were dark, and he was as calm as water, indifferent.

"Brother Feng, we are about to reach an altitude of eight thousand meters, you have to sit ...... tight"

Su Jinglu overwhelmed the control lever of the flank wind wheel, and then, the speed of the wind wheel was raised to the limit, and the ascent speed of the code name Meng Yu increased again.

At an altitude of 8,000 meters, it was clear, like a calm blue ocean, with a few clouds, like a dreamlike blue hue, perfect.

"The sky is beautiful, it's beautiful, it's like a peaceful ocean, it's breathtakingly quiet. Han Feng opened his eyes slightly, looked out the window, and couldn't help but let out a sigh.

"yes, I didn't expect it to be so dreamy here......"

Xiao Su smiled lightly, manipulated the connecting rod, controlled the code name Raptor, and continued to soar.

Call!

Phew!

Whew!

Immediately about to reach the stratosphere at an altitude of 10,000 meters, Su Jinglu controlled the code name Raptor, slowed down the speed of climbing, and the speed of the tail wind wheel began to accelerate, adjusting the overall coordination.

"Brother Feng, pay attention, when you touch the stratosphere, there may be a little instability!"

Airplanes!

Whew!

At this time, only the noise of the rotation of the wind wheel was heard, codenamed Raptor Raptor, and successfully passed through the troposphere to the stratosphere 10,000 meters above.

The air here is thin, there is no wind or clouds, and the friction of flight is reduced.

The raptor stopped climbing and began to move smoothly on the horizontal plane.

Shout!

Poof!

"It's not good, there is a situation...... Su Jinglu was full of surprise, and shouted, looking extremely nervous.

Hanfeng didn't know what was going on, just sat down, and suddenly, weightlessness in an instant, the code name Raptor lost its upward traction, and the top wind wheel seemed to have encountered a mechanical failure, and without any warning, the traction plummeted.

Call!

Shout!

Codename Raptor swooped down like a bird with folded wings, and in just three seconds, it descended more than 1,000 meters, and the speed of descent continued to accelerate.

Su Jinglu was already sweating profusely, and his two hands worked together to control the control lever of the lifting wind wheel.

Han Feng sat behind, dazed and at a loss, and his first reaction was to attract the true power of the earth and prepare to jump out of the window to escape.

8000 meters!

7000！

6000！

Codename Raptor fell vertically at a speed of one kilometer......

5000......

At an altitude of 5,000 meters, the lift wind wheel, which had been stopped, slowly resumed its normal rotation, and the power of the lift gradually returned to normal......

At an altitude of 4000m, the Codename Raptor regained its flight attitude, stabilized and no longer descended.

Su Jinglu was already sweating profusely, and his whole body was soaked.

"What the hell is going on, how can a bird of prey fall vertically......" The cold wind held his face red, and he was shocked, it was a bit incredible to encounter this kind of thing.

"The lift wind wheel, when it was in the stratosphere, stalled instantly!"

Stall means that the turbine blades of the wind turbine stop rotating in an instant, which means that it loses power.

There are generally only two reasons for a stall:

First, mechanical failure;

Second, energy depletion!

At the time of the drop to 5,000 meters, the lift wind wheel regained power, indicating that the wind wheel did not suffer mechanical problems and did not run out of energy.

"Stall ......"

Han Feng looked at Xiao Su with an expression of disbelief, and he was still a little scared in his heart.

Xiao Su settled down and fell into deep thought......

He slapped his head hard, and suddenly realized: "I know why it stalled, the stratospheric air is thin, and when the lift wind wheel rotates, there is no problem with the wind source energy provided by the wind element stone, it is a problem with the atmospheric pressure......"

The working principle of the lift wind wheel is that the air pressure above the rotating turbine blades is less than the air pressure below, and it is this pressure difference that provides the upward power.

The stratospheric air is thin, the inner pressure of the driving device is too large, the outer pressure is too small, the pressure difference exceeds the allowable range, the rotation of the wind wheel is abnormal, the system is disordered, and the stall is caused.

The upward momentum, which is far less than its own weight, has the phenomenon of vertical falling.

Vertical descent, power disorder, turbine blade speed disorder, instantaneous stall......

"Xiao Su, it feels so dangerous, in an instant, it landed vertically for several kilometers......" Han Feng recalled the scene of flying straight down just now, and it didn't feel very good.

"It's my mistake...... Xiao Su smiled embarrassedly and said, "After I go back, I need to improve the design parameters of the wind wheel to avoid the stall phenomenon......"

Stall for non-mechanical reasons can be corrected in time.

Otherwise, even if the two of them had a true power protector, if they fell from a height of 10,000 meters, the consequences would be unimaginable......

Codenamed Raptor circled in the air a few times before re-descending to Lake Celestial Realm......