Brother, this is an FMC failure! ”

Xu Qing had never seen an FMC fail before, but looking at the fault phenomenon, it should be eight or nine or ten.

"That's right, it's the FMC failure, you control the plane to keep heading, I'll report it to the control!" Yan Zhen said: "Blue Sky 9999, our FMC is invalid, apply for radar guidance." ”

Now the data displayed by the navigation is gone, and even the route is invisible, so the course can only be given by the control, and Xu Qing and they fly according to the guidance of the control.

Although the FMC is invalid, the heading can still be seen, at least the backup instrument is working, not that there is no navigation at all.

"Keep heading 200." Chen Yi gave a course, which is actually Xu Qing's current course.

Since the FMC on both sides is invalid, horizontal navigation and vertical navigation cannot be used, then use heading selection, correct the heading to 200, select altitude maintenance in pitch mode, and turn on autopilot again.

When the autonomous driving is turned on, you can divide your energy to deal with the fault.

There is a checklist for FMC failure!

Xu Qing is a PF at this time, and he should announce the abnormal checklist.

At this time, the effect of last night's "temporary cramming" came out. Xu Qing shouted almost without thinking: "FMC Failure" checklist!" ”

Yan Zhen quickly took out the QRH, and the "FMC Failure" checklist was in the flight management and navigation chapter, and after finding the checklist, the fault phenomenon was verified first.

The fault description of the FMC Failure checklist is the presence of VTK and MAP fault flags on one or both navigation displays.

Xu Qing and the others verified that the VTK and MAP fault flags in amber English appeared on the left and right sides of the navigation display respectively, which met the entry conditions of the "FMC Failure" checklist.

"Purpose! Use a single FMC, restore dual FMC operation, or resume traditional navigation. Yan Zhen explained the purpose of the checklist.

In the first line of the checklist, it is noted that the LNAV and VNAV may be disconnected, which is also in line with the current situation.

"Step one! Check both navigation shows MAP mode and FMC CDU! ”

This is the first step of the checklist, and now Xu Qing and Yan Zhen's navigation display is in the MAP way!

"Choose one or the other! If the pilot and co-pilot navigation show that there is no FMC data on the MAP mode and no FMC data on the two CDUs, then the two FMCs can be judged to be invalid. Yan Zhen said.

Yan Zhen pointed to the navigation display on Xu Qing's side, and then returned to the navigation display on his side and the CDU with black screens on both sides, and verified: "The navigation display on both sides has no FMC data, and the two CDUs have black screens, which meets the first option and enters step seven." ”

Here's why there is a saying "choose one" and "go to step seven".

That's because the same fault will have different fault phenomena.

When it comes to FMC failure, since there are two FMCs, there will be three cases: left side failure, right side failure, and both failures. Each of the three situations has different disposal steps, so there will be a saying of "choosing one of them", and it will be judged that it is a variety of faults.

So why is there a "Go to Step 7"? Where did the previous steps 2, 3, and 4 go?

As mentioned earlier, different fault phenomena correspond to different disposal steps. In this case, if the two-sided FMC fails, there is no such thing as using a single FMC to recover data, so we jump directly to the traditional navigation step.

As for Step 3, Step 4 and the like are all procedural steps to recover data using a single FMC, so naturally this case is not applicable.

"Step seven! Restore traditional navigation! FMC doesn't work, horizontal navigation and vertical navigation are not available! Yan Zhen said.

At this point, there is no way to recover FMC data artificially, and traditional navigation can only be used.

"Step eight, verify relative terrain position using traditional navigation."

One more thing to note here is that EGPWS may use incorrect GPS locations or inappropriate RNP values. This results in a positional error in the VSD terrain display relative to the aircraft track.

In other words, there may be errors in the use of VSD during the approach phase, so it is not recommended to refer to the VSD terrain display.

Not being able to use VSD isn't a big deal, it's not a big deal.

"Step nine! When preparing for an approach, use the speed reference selector to adjust the current full weight! Use the speed datum to set the baseline airspeed cursor! Use the N1 settings to adjust the N1 cursor. ”

This is the final step of the checklist!

Due to the lack of FMC data, the aircraft lacks some basic data, such as the full weight of the aircraft, the reference speed, and the go-around thrust, which need to be manually entered.

The speed reference selector and the N1 setting knob are on the left side of the automatic brake selector, and the adjustment method needs to check the performance table, but it is not needed yet, and it is not too late to get it when approaching.

"Blue Sky 9999, do you have any troubleshooting, do you still need radar guidance?" Chen Yi asked suddenly.

At this time, Yan Zhen just finished the checklist and immediately replied to Chen Yi: "Blue Sky 9999, our dual FMC fails, and we need radar guidance in the back!" ”

"Are you going to continue to fly to K City as planned?" Chen Yi asked.

"Yes!" Yan Zhen replied.

Although the FMC is unusable, the basic function of the aircraft has not been lost, and it can still fly, but it cannot enter the RVSM airspace, so there is nothing wrong with Captain Yan Zhen saying that he wants to continue to K City.

"The airport in K City is closed now." Chen Yi said.

Yan Zhen immediately changed his strategy: "Then we will return to City C and apply for radar guidance." ”

For Chen Yi not to let Yan Zhen continue to fly to K City, this is just a normal operation. There is no big difference between landing in K city and landing in C city, and it takes extra time to fly to K city, so it is better to return to C city, which can also save time and do more failures.

"Radar guidance, now we can't see you on the radar, we can't radar guidance." Chen Yi began to deceive.

Yan Zhen was also expected of Chen Yi's non-cooperation, if it was a real radar guide, then the meaning of this failure would not exist. This failure requires pilots to rely on traditional navigation for approaches and landings.

In the past, where the old aircraft or small aircraft had the electronic display of 737, the position of the aircraft could be displayed at a glance, and it was all based on each VOR station or NDB station, or even visual reference, to establish a spatial position in the pilot's mind. Therefore, in the past, aircraft were sometimes equipped with a navigator to share the pilot's navigation pressure.

Now it's different, the upgrade of technology has made navigation exponentially less difficult, and the navigator has gradually disappeared, until now there is almost no full-time navigator in sight.

Most of the time there is no need for traditional navigation, it does not mean that the craft of traditional navigation can be lost, in case one day the high technology is unreliable, pilots can at least rely on the original traditional navigation home, so it is always necessary to be prepared.

The failure of the dual FMC cuts off the pilot's navigation data page, leaving the pilot to rely on controlled radar guidance or his own traditional navigation.

In real flights, the control will basically agree to the radar guidance, so the navigation difficulty is actually not high, isn't it just to follow the command of the control to twist the course?

However, Chen Yi didn't give Xu Qing their radar guidance, just to let Xu Qing and them rely on traditional navigation and fly back to approach by themselves.

"That blue sky 9999, apply to fly FJC." Yan Zhen knew that Chen Yi's purpose was to no longer apply for radar guidance, and he wanted to fly back by himself.

FJC is a corridor entrance to City C, and Yan Zhen needs to fly to FJC first, so that it is easy to locate the aircraft.

"Agree to fly FJC, blue sky 9999, the nearby airspace has been cleared, you can approach by yourself, blind landing!" Chen Yi gave Yan Zhen great autonomy, and he wanted to see if Xu Qing's old skills had been lost.

"Xu Qing, do you have any ideas?" Yan Zhen asked.

Xu Qing is a PF, Yan Zhen gave Xu Qing enough respect, he already had a countermeasure in his heart, but he still wanted Xu Qing to make a decision first. If Xu Qing has no countermeasures, he will play again.

This traditional navigation method was often used when learning to fly small planes abroad. Xu Qing hasn't used it for a long time, but that doesn't mean he won't.

Xu Qing softly voiced, and he had to say a long sentence below: "Brother Yan, let's fly to the FJC's VOR, and then fly 10.3 nautical miles along the 353-degree radial line of the FJC." Then turn left to head 294, cut into the 294-degree radial line of the HLC station, fly until it is 8.4 nautical miles away from the HLC station, and then turn right and swing to cut the five sides of the 02R at the cutting angle. The 02R channel is 024 degrees, and if you have a 30-degree cut-in angle, you can head to 354. If you descend to the plan, you can go down to the height of 2400 meters when you get to the FJC, 1500 meters when you start to turn left to cut the radial line of HLC 294, and 1200 meters when you start to turn right to cut the five sides, and the height of the FAF is 1200 meters, so the margin of the descent plan is still very large. ”

Xu Qing combined the approach map and the blind landing map to plan a full set of descent plans, how to fly the course, how to go down the altitude are all clearly arranged, and Xu Qing's method is operational, not out of thin air.

The approach map and blind descent map that Xu Qing referred to were not commonly used RNAV methods, but traditional approaches.

Due to the failure of the FMC, the aircraft does not have the ability to locate the points in the RNAV chart, and can only refer to the traditional chart relying on VOR or NDB navigation stations.

Yan Zhen was slightly surprised, now many co-pilots are used to the convenient navigation display of the 737, and their memories of traditional navigation are becoming more and more sparse. When the co-pilot who was with him in the last retraining encountered the failure of the FMC, he couldn't find the direction in the east, west, north and south, but when he came to Xu Qing, the two complete sets of approach plans were clearly sorted out.

"Since you have a plan, do you still fly?" Yan Zhen said with a smile.

Xu Qing had to nod, he was actually not very willing to fly traditional navigation in his heart. This traditional navigation is not difficult, it is troublesome, and it is necessary to constantly switch VOR frequencies and channels, but when the captain speaks, he can only do it himself.

Just when Xu Qing and Yan Zhen were discussing how to approach, Wang Liang and Chen Yi in the back had already gotten together.

"Is this really okay?" Wang Liang couldn't help but be worried.

Chen Yiman didn't care: "It's all faults anyway, the same, the same!" ”

Wang Liang slapped his head, this chief teacher is really not provocative!

On the console control screen in front of the two of them, the screen that can display the real-time position of the aircraft, and the plane that is still moving does not move on the screen.

Console, stuck!

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