Time shifted forward slightly, and before the serious bump was about to start, when Yan Zhen and the co-pilot had just fastened their seat belts, there was actually some distance from the cumulus cloud in front of them.

The co-pilot tightened his seat belt and looked at the sky where his eyes were already obscured by dark clouds, and not far to the right of the plane's course, the mushroom-like thunderstorm clouds gave him strong psychological pressure.

Especially against the backdrop of darkening skies, the churning electric light in the thunderstorm clouds is like a raging beast lurking in it, exuding terrifying fear all the time.

Even though he was already far enough away from the thunderstorm cloud, the co-pilot still felt his heart flutter. It's not that pilots aren't afraid of dangerous weather, they are all flesh and blood, how can they all be saints who have collapsed in front of Mount Tai and their colors remain unchanged.

Compared with the co-pilot, Yan Zhen's expression was much more restrained, there was not much expression on his face, but the corners of his mouth twitched from time to time to reveal that Yan Zhen's inner pressure was not small.

You know, there was a thunderstorm cloud of the same size on their left, and they were crossing through the gap between the two giant beasts. To say that he is not stressed is to brag. Even in the so-called safe zone between two thunderstorm clouds, a large amount of cloud has accumulated, and it is not safe to survive if you want to pass it.

"Captain, we really can't go back to the flight, can this be worn through?" The co-pilot held back his thoughts for a long time and finally said it.

He was really scared! The thunderstorm clouds on both sides alone are really like two door gods, and they are completely idlers.

That's right, now the co-pilot just doesn't want to go in!

"Let's combine the weather radar and meet the company's thunderstorm flying standards, why can't we wear it?" Yan Zhen speaks with his head held high, but he is not the kind of person who speaks with his nostrils facing the sky, and now his demeanor is like this, it looks more like he is cheering himself up.

Yan Zhen said with righteous indignation: "If you say so, you will still fly for a ball in the summer!" ”

Every word Yan Zhen said was gritting his teeth, not to the co-pilot, but as if he was saying it to himself.

To be honest, what Yan Zhen said also makes sense. In the summer, the weather is often everywhere on the route. If you encounter some large-scale weather and return to the alternate landing at every turn, it is indeed impossible to fly.

Airlines have strict rules for flying around thunderstorms, which specify the safe distance from thunderstorms at different altitudes. This kind of regulation about flying around thunderstorms must have been carefully thought out and rigorously demonstrated, and it stands to reason that as long as a sufficient safety distance is maintained, there will be no problem, but it cannot withstand the psychological pressure of thunderstorms and lightning on pilots, especially in the background of low light.

Yan Zhen is better, after all, he is already a captain, he is well-informed, his psychological quality is not the same, and he can also restrain his emotions. The co-pilot is not in such a good mood.

"Blue Sky 834X, first go up to 8100 meters, keep!" That's when the control suddenly came with an order.

The co-pilot replied: "On the altitude 8100 meters, keep, blue sky 834X." ”

Yan Zhen didn't think much about it, 8100 meters is not much different from the current altitude, there is no difference, he adjusted the altitude of 26600 feet in the MCP, pushed a 1,000 feet per second ascent rate, and let the plane slowly get on.

Not long after the plane started to climb, Yan Zhen straightened the back of his chair, and was about to enter the clouds, so he had to be prepared.

The co-pilot saw that Yan Zhen had no intention of returning, although he knew that the suggestion of returning would basically not be adopted, but he was still cold in his heart, and seeing that the cumulus clouds were close in front of him, he could only go in hard.

"I was really dizzy and chose a flight major, how good it was to listen to my dad and take the civil service exam!" The co-pilot looked nervous as he grabbed the edge of the visor with his right hand and the seat with the other.

As he got closer and closer to Cumulus, the feeling of suffocation like a cliff made the co-pilot's little heart pound. He seemed to be able to hear his own heartbeat, which made him more and more irritable, and finally all his mixed emotions converged into a light sigh.

The volume of this sigh was very light, so light that Yan Zhen, who was close at hand, didn't notice it in the slightest. However, as soon as this sigh fell, the plane was plunged directly into a downstream.

It was like an invisible giant hand pressing on the plane, and one second it could maintain an ascent rate of about 1,000 feet, and the next second, the plane seemed to hit the dome of the sky, and the rising momentum was instantly stopped.

After the ascent was stopped, in order to follow the 1,000 feet per second ascent rate of the V/S method given on the MCP, the autopilot naturally thought that the plane could not go up because of insufficient power, and began to command the automatic throttle to increase up.

The speed that is almost visible to the naked eye, the throttle is increased from 80s all the way to 98, and at the same time, it continues to increase, and it is almost close to the limit.

Of course, under normal circumstances, the engine will not have an N1 overrun, because the engine itself has overrun protection, but it does not mean that the pilot can completely ignore the changes in the N1.

Even when the thrust was added to the limit, the plane still froze and could not rise in the slightest.

The ascent rate dropped sharply from 1,000 feet per second to near level flight, and due to the acceleration, the entire plane immediately felt like their butts were off their seats.

Yan Zhen naturally felt the feeling of floating up, and he immediately saw the rise rate on the lifting table, and he didn't know when it was actually zero.

"What's going on?" Yan Zhen asked meaningfully. Almost at the same time, Yan Zhen reflexively looked at the FMA indication on the PFD.

Yan Zhen's first thought was whether there was a problem with automatic driving, after all, the reliability of the Boeing 737 is good, but the workmanship is still relatively rough, and it is not impossible to occasionally have automatic driving convulsions.

The most intuitive way to see if there are any errors in autonomous driving is to check the display of the FMA at the top of the PFD.

Now the FMA displays MCP, LNAV, and V/S, and this FMA display is the expression of the normal vertical rate of autonomous driving, and there is no problem.

"What's the problem then?" Yan Zhen was a little puzzled for a while, and couldn't figure out what the situation was, until his eyes turned to the N1 display of the engine, and his heart suddenly jumped in shock.

What is the approximate range of N1 during normal cruising climb, this value will change according to the different performance of the aircraft and the density of the outside air, but it will never exceed 90, and now it is not only more than 90, but even close to the limit value.

This throttle plus maximum autopilot mode will only appear when the throttle mode of the autonomous driving is N1, such as altitude layer change climb or vertical navigation climb.

In the vertical rate automatic driving mode, as long as the selected lift rate and selected speed can be maintained, the throttle will not be increased, and if the throttle is increased to the maximum or decreased, the lift rate and speed requirements cannot be met at the same time, the lift rate will be guaranteed instead of the speed.

In the case of climb, for example, the rate of climb of 1,000 feet per second may not be achieved unless at high altitudes, resulting in maximum throttle. At less than 8,100 feet, it is unlikely that you will need to use the maximum throttle to climb at 1,000 feet per second.

There was a hint of weirdness in the matter.

In other words, it's not that the thrust is not enough, but that the plane just can't climb up, and something is stopping the plane from climbing up.

How so?

Because the speed has increased!

In the case of high thrust, an effective ascent rate cannot be formed, and additional energy can only be released by increasing the speed. At this point, the airspeed is increasing.

"What's going on?" Yan Zhen pointed to the engine instructions and asked the co-pilot beside him.

Even the captain can't figure out that the throttle is increased to the maximum, and the airspeed keeps increasing, but the rise rate cannot be formed, so shouldn't the priority be given to ensuring the lift rate? When did the vertical velocity approach become a priority to ensure speed?

Wrong! This is also not a priority to guarantee speed, which is now beyond the speed selected on the MCP board. This situation does not make sense anywhere, unless there is really a drag force that does not allow the plane to rise, and there will be a situation where only acceleration is now made, and no rise rate is added.

But there is nothing in the sky, what can hinder the ascent of the plane, it is extremely strange!

Even if the co-pilot has a dull brain, he can feel that something is wrong with the situation, and when he heard the captain ask himself, he muttered: "I ......"

Before I could spit it out, a more powerful downbeat bombarded the fuselage. At this time, not to mention rising, the plane actually entered the broken bird and fell down violently.

Halfway through the co-pilot's words, the state of the plane changed abruptly, and a stream of air poured saliva into his throat, choking the co-pilot's breath and rolling his eyes.

"ITM......" Yan Zhen now feels like the jumping machine that used to accompany people to the amusement park, if it weren't for the seat belt, the whole person would have to float.

It's exciting to have fun, but it's not a good experience to have on an airplane.

Weightlessness! A strong sense of weightlessness! Due to the drastic changes in the lift rate and turbulence, the plane may produce a short-term, slight feeling of weightlessness, but as it is now, it is comparable to the weightlessness of a jumping machine, and it is not fun to change it in the environment of the aircraft.

Why, why does the plane have such a sudden feeling of weightlessness!

Downburst? It is true that there will be a strong downburst near a thunderstorm cloud, but it is very rare to have such a strong downburst at such a high altitude and such a distance.

If the cockpit feels so strong, isn't the cabin going to turn upside down? Now what Yan Zhen thinks of in his mind is the condition of the cabin.

Yan Zhen thought about it well, now the cabin has indeed turned upside down, and now in the cabin, Xu Qing staged a scene of heroes saving beauty.

However, now is not the time for Yan Zhen to care about the cabin. When the plane fell suddenly, the throttle was still maintained at high thrust, and as soon as the plane fell, the airspeed index soared upward.

Fortunately, because of the bumps just now, Yan Zhen adjusted the speed a little lower, otherwise the speeding warning would have sounded early in the morning.

However, what is surprising is that the state of the aircraft has changed so much, and the automatic driving has not been turned upside down, which is really strong enough.

Yan Zhen saw that the speeding was imminent, but he did not disconnect the automatic driving, and under the strong bumps, the SOP recommended that the automatic driving be turned on, but the way of automatic driving should be changed.

"Engine starting, electric valve flight position!" While directing the co-pilot, Yan Zhen changed the connection mode of the autonomous driving from CMD mode to CWS mode.

The workflow of the CMD mode is that the FMC/MCP provides the target command - FCC calculates the rudder actuation momentum signal - electrical signal - hydraulic servo assembly - rudder surface.

The workflow of CWS mode is the steering wheel - sensory force sensor - FCC calculation rudder surface actuation momentum signal - electrical signal - hydraulic servo assembly - rudder surface.

If the CMD mode is the most standard and most commonly used automatic driving mode, then CWS is a semi-automatic mode, at this time, the aircraft only takes over the trim, not the steering wheel, and the pilot can input the control signal through the steering wheel, so as to intervene in the work of automatic driving.

However, in CWS mode, the input signal via the steering wheel needs to exceed a certain limit value in order to be a valid input.

The starter valve flight position is only used in memory items where heavy rain, severe turbulence and loss of thrust are used. Now it is not only in a severe turbulence, but also about to enter the cloud area, which may be accompanied by heavy rain, it is better to preemptively open the starting door to fly in position.

The co-pilot was choked by his own saliva, and almost turned his back on his breath, but only when he heard Yan Zhen's words did he come to his senses, and quickly shook his spirits, and reached out to turn the engine starting valve to the flight position.

Switched to Yan Zhen's side, after using the CWS mode, he took a lever, intervened in the automatic throttle, and retracted the throttle slightly. This belt lever, as soon as the throttle is closed, the speed is reflected and begins to drop sharply.

When at high altitude, if you can't blindly close the throttle in order to slow down, in case you collect too much, and then refuel the throttle back, the throttle is hysteresis, and in the high-altitude environment, the air is thin and the aircraft performance is poor. Once the throttle is retracted too much, the speed can shift from overdrive to too little, triggering a stall jitte.

Therefore, it is necessary to be cautious enough to decelerate the throttle at high altitude.

After Yan Zhen intervened in the autothrottle, he saw that the speed had slowed down, and immediately withdrew his strength and did not interfere with the work of the autothrottle.

The downburst just now lasted only a moment, and the plane suddenly dropped more than three hundred to nearly four hundred feet in height. After that, the plane stopped falling, and before Yan Zhen and the co-pilot could catch their breath, another downward air force made the plane bow its head again. It's just that this time the downward air flow is really much softer than the one just now, and the altitude of the plane has only dropped slightly, not even a hundred feet.

In this way, the plane encountered a continuous downward airflow, although it did not have the horror and strength of the first time, but it was always pressed against the plane and could not climb. The plane is in a stepwise downward spiral all the time!

That is, after a downward blow of airflow, the plane is just about to raise its head, and another downward blow of air flows down, instantly extinguishing the upward trend of the aircraft.

The only luck is that the airflow after the downward attack is far better than the first one, and when the plane stabilizes slightly, Yan Zhen controls the plane and orders the co-pilot: "Ask if anyone is injured in the cabin." ”

As soon as the co-pilot turned the transmitter into the cabin, the voice of the controller sounded in the earphones of the two: "Blue Sky 834X, what is your situation?" No more up, there is a conflict! ”