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After receiving the call from Di Qingquan, even though Xu Cang was not very willing, he had to temporarily arrest a backup staff to replace Xu Cang. Xu Cang changed to a crew and flew to Wucheng. He checked and found that there was no need to mention Erhai Lake, and Jianchuan did not have a direct route to Shule Airport.

Although Shule Airport is a border port airport, it is still not big after all. Moreover, there are more cargo planes there, and the passenger flow is not large, so it is normal not to fly directly.

However, Wucheng was not too far from Shule, so he sent a message to Di Qingquan, explaining that his itinerary was arranged and he packed up and boarded the plane to Wucheng.

After three and a half hours of flight, after landing at Wushi Airport, I originally had to take a navigable plane to Shule Airport. However, the time for the navigable plane did not match, so I had to wait at the airport for more than four hours. Di Qingquan should have figured out the situation and arranged a car to pick up Xu Cang at Wushi Airport, which was very careful.

Shule is about two hours' drive from Wucheng City, and there is almost no bump on the newly built highway. Xu Cang fell asleep soon after. When he woke up, his car had already arrived near Shule.

The car headed straight to the airport. Unlike Xu Cang's impression that there were droughts in the northwest, Shule Airport was lush and green, as if it was an oasis. There was also a lake with pleasant scenery to the east of the airport, with birds flying over the lake. If you can visit here in your spare time, it is also a good place to go.

Before entering the airport, Xu Cang could already see a Boeing 737 of National University of China Airlines parked in a corner of the apron. If you guessed correctly, this 737 was an aircraft that had previously participated in the single-transmission program verification at Qitai Airport.

The reason why I chose CNY Airlines to support the aircraft is that CNY Airlines is the only airline that bears the national emblem and needs to bear the responsibility it still has. Secondly, CNY Airlines has its own branch in the northwest, which is very large and is the largest airline in the northwest region, namely CNY Northwest.

With this branch, it is relatively easy to provide logistics support for aircraft deployment and subsequent maintenance. Overall, it is necessary to support this verification flight.

The car did not put Xu Cang in front of the departure floor or the internal safety passage entrance. The driver briefly explained the situation to the security checkpoint staff. After showing the ID, the safety staff simply checked the vehicle and let it go.

After walking through the internal passage, the speed was naturally very fast. After entering the airport, the car did not go under the plane, but pulled Xu Cang to a VIP lounge at the airport. Xu Cang got out of the car and pushed the door open. Some people had already sat in it, including Bi Lin, Di Qingquan, and Chen Guoli, but the instructor of the National University of Aviation was not here.

"Xu Cang, you are here. Thank you for your hard work along the way. Come and have a cup of tea first." Bi Lin sat in a big golden sword, putting his hands on the crutch, his face was solemn, but his tone was still normal.

In comparison, Di Qingquan's expression was the most relaxed. As soon as Xu Cang came in, he stood up and called Xu Cang to sit down, very enthusiastic.

As he walked over, there was water on the plane and on the car, but Xu Cang was not thirsty. The only thing he cared about was naturally the matter at Qitai Airport. As soon as he sat down, his eyes fell on Chen Guoli, who had a melancholy face in the corner.

"Teacher Chen, can't fly to Qitai Airport?"

Xu Cang's words were really impolite because it was quite questionable. However, Chen Guoli, who knew that he was in the wrong, had nothing to complain about. He volunteered and ended up in a mess, and he had no stance to be angry.

"Teacher Li from the National University of China is determined not to fly anymore. I can still fly. I have said before that I can stay in Qitai, but I am afraid that I will not be able to complete the mission."

The meaning is very simple. Now the main contradiction is not whether Chen Guoli dares to do so, but that Chen Guoli has begun to doubt himself. If he sacrificed his life to complete the task, Chen Guoli would not be so frowning.

The instructor of National University of Aviation did not have the awareness of Chen Guoli, so he directly gave up.

Di Qingquan comforted from the side: "Teacher Chen, I heard Teacher Li talk about the situation at that time. I know in my heart what Qitai Airport looks like. It's not that you are not capable enough, but that Qitai Airport is a bit too difficult for civil aviation aircraft."

Xu Cang did not agree, but said bluntly: "Teacher Chen, what do you think is the difficulty? Let's talk about it?"

"I, the defeated general, have the face to explain it to you?" It seems that the failure of Qitai Airport has caused a great blow to Chen Guoli, and now he is obviously lacking in confidence.

As a result, Bi Lin snorted coldly: "Flying is originally about communicating with each other. What defeated general? After coming down, what am I blaming you?"

Chen Guoli's face turned red and hesitated for a moment, and finally said: "In fact, it's the third person, the ground skating, the wind is strong, and the mountains are high. First of all, this surface problem! The airport has calculated our landing time in advance and sprayed anti-icing liquid on the runway. Logically, when we landed, even if there was snow and ice accumulation on the road surface, it shouldn't be too serious. But in fact, due to the side wind, there was a little side slip when the first grounding was grounded. It was this side slip that the plane almost lost control, which led to the first re-escape. Later, we tried it a little, and even if we sprayed anti-icing liquid and sprinkled salt on the runway, the effect was quite poor. At the fastest time, I didn't hold on for five minutes."

"Xu Cang, there are many winds and snows at Qitai Airport, so there is basically no running track. For slippery roads, you must be mentally prepared. The airport can provide some help, but it is impossible to completely eliminate ice and melt snow." Bi Lin added from the side.

"I never thought of falling on the runway at Qitai Airport." Xu Cang was so excited. However, he thought again: "If the two wheels land at the same time and there is no side slippage, even if the road surface is slippery, it should not be out of control after landing."

"But the problem is that under that kind of turbulence, I can't make sure that the plane has no side slippage, and that kind of precision is difficult to complete." Speaking of this, Chen Guoli felt even more ashamed. Eliminating side slippage during the grounding process is a simple technical problem, but he just wasn't sure to complete it.

"I barely landed the plane after three trials." Chen Guoli's eyes showed a light at this time: "Xu Cang, are you sure that you can directly eliminate side slippage before grounding in a strong wind environment?"

This question is difficult to answer. From a personal point of view, Xu Cang felt that it was not that difficult to eliminate side slips. However, he had not flew past Qitai Airport, and at least it was definitely not easy to scare away the National University faculty. As the saying goes, there are mountains outside the mountain, so he still didn't want to say too much, so as not to slap himself in the face.

However, before Xu Cang answered this question, Bi Lin was a little displeased: "Guoli, what does it mean to ask such a question at this time?"

In Bi Lin's opinion, Chen Guoli's question is quite similar. However, Chen Guoli really doesn't. He just asked questions from a technical perspective. After Bi Lin said this, how could Chen Guoli dare to continue speaking?

"Teacher Chen, what kind of strong wind do you think of Qitai Airport? " Xu Cang asked.

"Uh, I won't talk about the wind volume against the wind. The gust is eighteen meters. If it is the side wind, the maximum wind volume of the positive side wind can be close to twenty meters."

"Twenty meters?" Xu Cang was stunned: "Isn't this definitely exceeding the standard?"

Not only is the 20-meter cross wind on the wet runway, but even if it is dry, it cannot fall.

Xu Cang looked at Di Qingquan and said, "Chief Master Di, this is the air volume exceeding the standard."

Di Qingquan's face looked a little embarrassed: "Xu Cang, you have to know that this is not a commercial operation. The rules of Part 121 do not apply. The crosswind does exceed the standard, but it does not mean that the plane cannot land. Moreover, if you have to wait for the wind to be low, then you have to wait for the spring to begin."

The air volume limit of 737 is not that it cannot be lost if it exceeds it, but that it will be greatly reduced if it exceeds the safety factor.

"Then let's wait for the spring to verify it." Xu Cang said naturally.

"Koqitai Airport only has a smaller wind in two months of spring, and the other ten months are similar." Bi Lin said: "We should not prepare for the best situation, but plan for the worst situation."

Xu Cang asked back: "Then safety cannot be guaranteed."

Bi Lin's eyes were bright: "Xu Cang, don't you know what Qitai is doing? When necessary, you have to make choices."

Xu Cang breathed suffocated, and Bi Lin's decisive attitude was almost made clear. Xu Cang did not continue to have an excessive air volume. Moreover, from a personal standpoint, strong wind is a very critical issue, but it is not enough for the National University of Aviation instructor to escape directly by looking at the wind.

To be honest, when civil aviation management is not serious, sometimes the air volume exceeds the standard, and the pilots are still on the verge of falling down? However, when the various regulations later become more and more stringent, such things are almost eliminated.

However, simple strong winds are not fatal, and strong winds and slippery road surfaces are the most fatal. Due to the grounding habits in strong winds, many pilots will eliminate side slip only after grounding. Few pilots eliminate side slip in the air like Chen Guoli, which is already considered an advanced technique.

However, eliminating side slip after grounding does not work at Qitai Airport. Eliminating side slip in the air is difficult to operate because there is no fulcrum. Moreover, the reference object is not as good as grounding, and it is really difficult to directly eliminate side slip.

But even so, Chen Guoli finally fell into trouble? Although the process was a bit ugly, the result was still acceptable. How could he scare the National University of China's teachers like this?

"Teacher, you continue."

Chen Guoli first glanced at Bi Lin, and then said: "Actually, if only these two things are there, I feel that the problem is not that big. At least Teacher Li should be acceptable. The problem lies in the third lap, which is that Teacher Li came to fly in this lap."

Xu Cang raised his eyebrows: "What happened?"

"It almost happened." Chen Guoli seemed to be still scared when he thought about it: "When the third lap was approaching the high level of decision, Instructor Li felt that the plane was in poor condition, so he returned to the flight. We brought a lot of fuel at that time and were ready to go back many times. It was nothing to pull it up in poor condition. As a result, the plane had just pulled up and had not been climbing for a long time. At that time, I didn't pay attention to the specific amount of the tailwind to turn, but Instructor Li reacted quickly and immediately added the maximum throttle, but the plane just couldn't get up."

Speaking of this, Chen Guoli couldn't help swallowing his saliva, his face slightly pale: "There is a mountain on the side of the re-flying runway No. 28. At that time, I felt that the plane was about to hit the mountain. Fortunately, the tailwind shear did not last long, and finally it almost passed the mountain."

"Looking back now, fortunately, we did a quick return flight. After flap fifteen, we immediately closed the landing gear. If we brought the landing gear in the air shear, even if the wind shear decreases behind us, we would not be able to go over the hill, which is too dangerous." Chen Guoli sighed: "It was this time that Teacher Li was really scared. He originally came to the back circle, but he pushed it to me. Then after landing, he said he would not fly."

Di Qingquan looked a little stiff. This time, the experience at Qitai Airport was probably going to leave a considerable psychological shadow on Teacher Li of the National University of China.

"Shearing with the wind." Xu Cang's face was also quite serious.

Downwind shear is indeed quite fatal. If you encounter it, the performance of the aircraft will be greatly reduced at once. The extreme is like Chen Guoli encountered it. The aircraft has the maximum thrust with both transmissions, and the aircraft just can't climb.

It's fine if you want a plain airport. If you can't get up, just wait a while. It's not like hitting a tree. But around Qitai Airport, the trees can't hit a mountain. The clearance conditions around Qitai Airport are so bad that they don't have much obstacles at all. It's not unreasonable that Teacher Li was scared. He really walked away from the gates of hell.

"However, Xu Cang" Chen Guoli suddenly said: "Although I haven't really flew a single shot behind me, from the feeling of flying, the single shot program doesn't look very reliable."

Now, Bi Lin and Di Qingquan also cast attention to Chen Guoli, and Bi Lin even said directly: "What do you mean?"

"At the beginning, I thought that although Qitai Airport was very high in altitude, it was surrounded by low temperatures all year round, and its aerodynamic performance should not be too poor, but I actually flew down, and the performance seemed to be reduced a lot."

It is normal to have high altitude, thin air and poor aerodynamic performance. However, the high density of cold air will increase the aerodynamic performance of the aircraft to some extent, thereby offsetting the impact of high altitude on the aircraft's performance.

However, from a personal perspective, Chen Guoli did not feel this compensation.

"I don't have real data support, I just talk about my personal feelings." Chen Guoli paused: "This is not the most deadly. I carefully looked at the single-shot program map and compared the topographic map of Qitai Airport. I found that the obstacle-over-reaching limit of the second and fourth stages of the single-shot program is strictly only thirty-seven feet."

"Thirty-thirty-seven feet?" Xu Cang had no intention of participating in the verification, so he didn't care about the so-called single-shot program at all. He just came here to watch some on the plane this time, but he had not studied it as carefully as Chen Guoli.

Not to mention anything else, Chen Guoli's attitude alone is definitely awesome, and it seems that he really regards this matter as the object of research.

Xu Cang's face looked a little unfavorable: "Isn't that two feet higher than the minimum standard? The terrain around Qitai Airport is very complicated, but as for the Yudu left so small? No, there is no Yudu at all."

Under normal circumstances, that is, when the dual-engine works normally, there are two sections that need attention for the instrument departure procedure, that is, climbing two gradient sections 2.5% and 3.3%. In fact, the interval of 0.8% difference between these two sections is a residual space.

According to requirements, obstacles cannot be higher than 2.5% gradient profile, and the aircraft's climbing trajectory cannot be lower than 3.3% gradient profile. However, this is not unchanging or has no room for rotation.

For example, if an obstacle wants to break through the 2.5% gradient profile, then the instrument exit program diagram must mark a specific climbing gradient, such as a 4.8% starting climbing gradient to meet the obstacle crossing requirement. It should be noted that the final starting climbing gradient is the value after adding 0.8% of the residual space, rather than the real obstacle crossing gradient.

If the aircraft cannot meet this starting climb gradient, the load must be reduced, otherwise this program cannot be used.

In comparison, under normal circumstances, the requirements for obstacle crossing are relatively simple and the standards are relatively unified. However, in the case of a single-engine, below 1,500 feet, the climb of the aircraft is divided into four stages, namely, the four stages of takeoff.

The four stages of takeoff include off the ground, after the wheels are closed, growth rate and green dot climbing. Among them, the only requirements for climbing gradients are after the wheels are closed and green dot climbing, which is what Chen Guoli calls the second and fourth stages.

The first stage of the ground only requires a positive rise, and at the same time, it is necessary to pass over the runway head at a height of 35 feet. In the third stage of the growth rate, the aircraft only needs to not drop, that is, the lifting rate is greater than or equal to zero.

Among them, the second stage is that the climbing gradient after the closing wheel is greater than 2.4%, and the fourth stage is that the gradient of green point climbing is greater than 1.2%. As for the obstacle-surfing balance mentioned by Chen Guoli is not calculated based on these two gradient trajectories, but also 0.8% of the gradient balance must be subtracted. The vertical interval between the curve after subtracting the balance gradient and the obstacle is the obstacle-surfing balance.

According to the provisions of 25 airworthiness certificates, aircraft should ensure that when a single round is launched, all four stages can meet at least thirty-five feet of obstacle crossing. The first stage is calculated based on the runway head.

There is an old saying that the law is the lowest moral standard, and the provisions in civil aviation regulations are naturally the lowest. When designing procedures, the greater the obstacle, the better, so as to give pilots room to move.

But the single-send procedure of Qitai Airport is only 37 feet away from the obstacle. That's right, according to regulations, this single-send procedure is in line with it, but if the design institute is not trying to save trouble, then Qitai Airport really has no room for evasion, and there is no way out of the design institute.

"The 37-foot obstacle-surfing residual. If a low-altitude tailwind shear is encountered during a single-shot climb, the climbing gradient will be hard to say." Chen Guoli said earnestly: "In fact, it is not difficult to reach a gradient of 737 in a single-shot situation. However, if possible tailwind shear is added to the high-altitude area, the residual is so small."

At the end, Chen Guoli felt Bi Lin's cold gaze, and suddenly trembled and immediately shut up.

This kind of words are quite convincing from the eyes of Qitai Airport. Moreover, Xu Cang was not very happy to get involved in this matter, and now hesitated.

Seeing Xu Cang want to speak but stop, Bi Lin said in a deep voice: "Say whatever you have."

"Dean, then I'll just say it." Xu Cang coughed gently: "Or why not forget it this time."

As soon as these words came out, Di Qingquan couldn't sit still: "Xu Cang, you promised to be the candidate."

"But now, the situation does not seem to be a little dangerous at the beginning, it is very dangerous." Xu Cang said helplessly: "Chief Master Di, you should know that in a single-shot environment, the ability to resist strong winds is poor. If you encounter a tailwind shear, there is really no way to do it. Moreover, the escape distance for me is so small. To be honest, my operating space is very small."

Di Qingquan's expression condensed, and he couldn't say a word for a long time. At Yulong Airport, he had already morally kidnapped Xu Cang once, and he really didn't want to force Xu Cang again in the matter of Qitai Airport.

So Di Qingquan opened his mouth and finally didn't say anything.

For a moment, the entire lounge fell into a strange silence.
To be continued...