Chapter 23: The tip of the knife dances, turning in a stall!
From the moment the engine problem occurred during the takeoff roll, the captain was in an extremely tense state of mind, and some of his reactions were understandable, such as overreacting by executing the memorized items on the engine fire, severe damage or separation checklist.
Xu Cang's action undoubtedly woke up the captain. The captain was just tired, not weak. Almost instantly, the captain realized his mistake and immediately retracted his right hand from the thrust handle of the No. 1 engine.
He gently pulled the APU starter switch and looked back from his left side window, but he could not see the runway of Jianchuan Airport. Because the runway was right behind the plane, it was already in the blind spot of vision. However, what really puzzled the captain was the direction of the turn that Xu Cang had chosen.
"Why not turn right?" The captain's mind became clearer at this moment.
"The sideslip and wind will make us move further and further away, and we won't be able to turn back." Xu Cang's answer was quite brief.
At this moment, the stable crosswind is blowing the plane from left to right, and even though the thrust of the No. 1 engine is constantly decreasing, this also means that the sideslip of the plane is constantly decreasing, but it does not mean that there is no sideslip. As long as the sideslip exists, the plane will have a tendency to deviate to the right. At this moment, if the plane chooses to turn right... Under the influence of the two positive feedback factors, when the crew turns 180 degrees, they will find that the plane has deviated to the left side of the runway for a considerable distance.
When there is motivation, this may not be a big enough problem, but when there is no motivation, it becomes an extremely difficult problem.
Engine No. 1 still had its last bit of stubbornness. It was still running hard in the burning flames, but Xu Cang was very clear in his mind that this was just the reaction of the engine's last gasp.
"But to the left, can we turn around?" the captain expressed concern.
Xu Cang's expression remained unchanged: "If you can't turn around, then increase the slope!"
"But on a steep slope, the altitude will drop very quickly and we won't be able to make it to this field."
"Then you should pray that Engine No. 1 can burn a little longer."
The exchange between Xu Cang and the captain was extremely brief, but it was just like a normal chat between ordinary people. However, at the end, the captain was obviously unable to hold back, and he gritted his teeth with every word he spoke.
It was obvious that the captain couldn't help getting nervous, especially after he discovered that the plane couldn't turn at all.
Whether it was the wind or the residual thrust of the No. 1 engine, they were preventing the plane from turning left, which was exactly what the captain had been worried about. Xu Cang was relatively conservative at first, using only a slope of about 20 degrees. This was not an overly conservative slope for a single-engine plane with flaps down, but it was obviously not enough to cope with the current situation.
Although the turning slope was formed, the change in heading was extremely slow. If this situation continued, the plane might not be able to turn even when it flew over the runway.
The captain said anxiously: "The wind is too strong, and the turning slope is limited in single-engine mode. We can't turn at all."
"If I can't turn, it only means that the slope is not big enough. There is no need to worry about the slope limit at this time!" After saying that, Xu Cang simply ignored the limit on the turning slope due to lack of power and directly increased the slope to between thirty and thirty-five degrees.
"Notify the cabin to make an emergency landing immediately and prepare for collision avoidance." The sweat on Xu Cang's forehead dripped down along his eyebrows, slid across his cheeks, and moistened his lips. Xu Cang pursed his lips. He could feel his heart beating wildly, and a huge amount of fresh blood was transported to his limbs. He urgently needed it now.
"If possible, declare MAYDAY, apply to the control center for on-site evacuation, and request ground support."
Previously, Feiyu 6321 declared a PANPAN state, which is a lesser emergency state than MAYDAY. But now it has obviously exceeded the definition of PANPAN and needs to be re-declared as an emergency state, which is MAYDAY.
The situation was urgent just now, and Xu Cang only reported his intentions without updating the emergency status. Now he needs the captain to help him do all this, and the request for evacuation on the spot after landing must also be reported.
The captain didn't hesitate. As soon as Xu Cang opened his mouth, he was ready to notify the cabin crew. But when he saw the PFD display, he broke out in a cold sweat.
At this moment, the aircraft's airspeed was just at the top of the red and black speed band of minimum speed, and the pitch limit indicator shaped like a small eyebrow was tightly attached to the aircraft's attitude indicator.
Although the No. 1 engine still has some residual power, it is not enough to provide the additional downward trend of the aircraft when turning. Why is it that after takeoff, the two engines lose thrust and it is often impossible to return home? Is the problem in turning?
Once the plane turns, the lift generated will be broken down, which means the plane will lose altitude faster. Five thousand feet is already not enough for a straight twin-engine glide, not to mention the plane is turning?
The power of the No. 1 engine is not enough to support the aircraft to turn while maintaining sufficient maneuvering speed. This has nothing to do with the crew's control ability. It is determined by the purest laws of physics, and no one can change it.
Therefore, Xu Cang had to choose between high speed and speed. Obviously, Xu Cang felt that height was more important, so he decided to release some kinetic energy, that is, to slightly pull the steering wheel to stop the plane's downward momentum.
But without enough power, this action is a standard deceleration behavior. Therefore, not long after the bank angle of more than 30 degrees was formed, the speed of the aircraft dropped from the maneuvering speed of flap 1 to close to the stick shaking speed.
Since the plane formed a slope of more than 30 degrees, the change in the plane's heading began to become obvious. Based on the heading of Runway 05, Xu Cang calculated that they would need to maintain this slope for a while.
However, the plane was already beginning to fail! The plane's altitude was still precarious, and Xu Cang couldn't let go of the steering wheel. He had to keep it in the state of holding it, which meant that the speed was still higher than the sacrificed one.
"It's going to stall, it's going to stall!" The captain saw that Xu Cang had not yet let go of the stick and was still holding it, so he shouted sharply: "Let go! "
The captain's hair stood up all over his body . At this moment, the plane was not only turning, but also skidding slightly.
What is a stall with sideslip? It is a tailspin! As long as a gust of wind blows, the plane will roll over without any control, without any chance of survival.
However, the captain's reminder did not stop Xu Cang's operation. He was still holding the control wheel. The speed of the aircraft immediately broke through the red and black speed bands, and the attitude indicator also passed the pitch limit indicator. At the same time, the signal sent by the stall management computer instructed the two control wheels to start shaking.
The plane is shaking!
