In fact, the Maneuvering Characteristics Augmentation System activates the MCAS when the aircraft is in autopilot and the flaps are closed, and the crew does not give a stabilizer trim command, at which time the AOA angle exceeds the threshold value, which is calculated based on airspeed and altitude.

After takeoff, it has been manually controlled, and then experienced unreliable airspeed and suspected loss of control of the stabilizer, so that the automatic driving has never been turned on.

Xu Qing now recalled that the maneuvering characteristic enhancement system only started working after the flaps were retracted, but he didn't verify it when the flaps were lowered, so he couldn't be sure.

However, it is enough to be able to understand the mode of operation of the maneuvering characteristic enhancement system.

"What you want to reopen the stabilizer and cut off the electric door?" Instructor Chang asked, Xu Qing said so much, didn't he just want to show that he could put the trim under control now.

Xu Qing nodded: "Without matching, it is always very troublesome to manipulate." Master, you can use the main electric trim normally, as long as I find an abnormal trim, I will use the main electric trim on my side to suppress the maneuvering characteristic enhancement system. Master, believe me! I wouldn't let the anomaly trim exceed 0.5 units! ”

0.5 unit balancing, which means that Xu Qing is sure to control the abnormal balancing within two seconds!

Teacher Chang was quite pleased with Xu Qing's confidence, Xu Qing was so confident in today's situation, and he already had the potential to become a good captain. However, Teacher Chang did not intend to agree to Xu Qing.

Now the state of the plane is within the normal trim range, with Xu Qing's handling level, it will feel very uncomfortable without trim, but for him, the plane is in a stable state now, and there is no need for trim to cooperate with the correction, and he doesn't want to make any more moths. Even if he felt that Xu Qing's analysis was right.

For the sake of a dispensable trim, there is no need to take risks!

"No need, keep it closed, I don't care if it's trimmed or not." Teacher Chang said firmly.

For the choice of regular teachers, Xu Qing did not insist. There are pros and cons to re-opening the stabilizer to cut off the electric door, and Instructor Chang is confident in his manipulation skills, so he also respects Instructor's choice.

At this moment, the voice of the tower sounded on the radio again: "Blue Sky 9433? ”

"Blue Sky 9433, answer!" The current situation is not as urgent as just now, and Xu Qing still returned to the tower control.

"Blue Sky 9433, confirm the current status of the aircraft!" Hearing that Blue Sky 9433 finally had a reply, the tower control finally breathed a sigh of relief, and at this time there was a duty director standing behind him!

Xu Qing: "Now the plane has some failures, but the status is still under control, and I have applied to return home." ”

Just after the interval of replying to the control of the tower, Instructor Chang told Xu Qing about the decision to return to the flight.

"Blue sky 9433, you can turn right to course 030, rise altitude 3900, and correct sea pressure 1012." The tower control gives instructions.

Xu Qing frowned: "Tower, do you think you can turn left and take the left three sides?" ”

The clearance conditions on the left side are obviously much better than those on the right side, and now that the aircraft has problems, it is safer to choose a return route with better clearance conditions.

For the crew, the left three sides are indeed more preferred, but for the control it is different. If Blue Sky 9433 turns left, it will seriously affect the take-off of runway 22, and the entire release plan will be disrupted at that time.

Sure enough, the tower control immediately rejected Xu Qing's application: "Blue Sky 9433, turning left has an impact, so I can only agree to turn right." ”

"If you're going to turn left, you can declare a state of emergency!" Tower control added. Just as the tower control said this, the duty director behind him frowned imperceptibly.

As long as the crew declares a state of emergency, the control will give it all the priority, and at that time, does Blue Sky 9433 want to turn left or right, not with the crew idea?

But there's no such thing as a free lunch, and giving it great priority means it will affect other flights, especially hubs like K. If an aircraft declares a state of emergency at will without meeting the conditions for declaring a state of emergency, the bureau will definitely make it impossible for the crew to walk around.

At the end of the day, declaring a state of emergency is a final card that needs to be done with caution.

In fact, now that the plane is basically under control, it is too much to declare a state of emergency for the sake of a left-turn application, and to the displeasure of the regular instructor, the tower control is suspected of inducing the crew.

The situation of the plane is indeed not as urgent as it was just now, and the second hill is not as wide as the first, and it can be avoided well by turning left. Of course, if you keep climbing as you are, you shouldn't have a problem crossing the second hill. Xu Qing applied for a left turn just to reduce the risk to zero.

Just when Xu Qing and others declared a state of emergency, the EGT of the second engine suddenly exceeded the limit, and in just a few seconds, the N1 of the second engine began to fluctuate significantly, and the plane appeared intermittently unstable at the same time.

"Damn it!"

Instructor Chang just glanced at the engine data and showed that one foot against the left rudder, the second throttle lever was directly retracted, and he shouted: "Cut the second start handle!" ”

Xu Qing's eyes were quick, and at the moment when the instructor gave the instruction, his left hand put on the second-engine handle, and he immediately cut it off.

Even in such an emergency, the instructor still follows the procedure and cuts the throttle by himself, and the starting handle is operated by Xu Qingche, who is the PM.

The second engine is overheated again, and it can no longer continue, and the whole engine will be scrapped if it continues for a while!

I have to say that the engine performance of the MAX is really powerful, even if it loses an engine, the climb rate is reduced, but it does not lose too much, mainly because there are not many passengers on the plane this time.

Even so, relying on a single engine to overcome obstacles is a bit stretched.

"Blue Sky 9433, we have a second malfunction and apply to turn left." Xu Qing continued to apply.

"Blue sky 9433, turning left has an impact, are you going to declare a state of emergency?" The tower control still wants to clean itself.

It is everyone's instinct to protect oneself, and when the crew declares an emergency, he has great dispatching authority. If the crew does not declare an emergency, then he can only dispatch within the normal scope of authority, there are too many constraints, if there is a problem in any link, he will be responsible.

"Blue Sky 9433, you can't turn right, do you think it's okay to keep course, go to altitude first, and then turn right?" The tower offered a compromise.

Xu Qing's anger came up all of a sudden, and this tower was stunned because he didn't want to get a little water, and repeatedly asked them to declare a state of emergency. But now, even if the second engine is lost, the plane is still under control, and there is no need to declare a state of emergency!

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