Return to 2000: Captain of the Great Powers
Chapter 190 Falling into the Sea!
Chapter 190 Falling into the Sea! (Please subscribe!)
Those two completely different surge sounds were constantly hitting Xu Cang's heart like heavy hammers.
For a four-engine aircraft like the 747, the impact of one engine failure is not as great as for a twin-engine aircraft.It is precisely because of the existence of this huge margin that the four-engine aircraft does not need to comply with the ETOPS standard.
However, if the second and third engines also stalled, the situation would be completely different.
"It started to surge again?" The responsible captain also heard the sound of surge, and his eyes drifted away from the N1 speed for a moment.Sure enough, the N1 speed of the No. [-] and No. [-] engines has begun to become unstable, which is also one of the signs of engine surge.
"Tell Jakarta control that we will carry out single-engine drifting." Xu Cang said immediately.
The second captain was taken aback, obviously puzzled by Xu Cang's way of drifting down: "Don't you keep the altitude? Isn't the volcanic ash thicker when you go down?"
"There are only three engines left now, and two of them have surged, and they have to descend if they don't descend." After that, he needs to reduce the thrust of the No. [-] and No. [-] engines, at least to ensure that they will not stall.Once turned off in this environment, it is likely that it will not be restarted.
And as long as the No. [-] and No. [-] engines are operated with reduced thrust, most of the power demand will be put on the No. [-] engine, which is obviously beyond the capacity of the No. [-] engine.
What's more, running in the volcanic ash area, high thrust and high speed are more likely to cause damage to the engine. Xu Cang is not willing to have problems with the only No. [-] engine that is still running normally.
The captain in charge thought for a moment, then nodded heavily.Before that, the three engines were normal, and it didn't matter if one engine was scrapped.If it is still strong now, there is likely to be only one engine left, and it is unknown whether this engine can last.
In the final analysis, it was too reckless to cut the No. [-] engine by myself.If it can be kept above [-] feet, it is almost at the upper edge of the volcanic ash area, and the concentration of volcanic ash is not high.The remaining three engines that can still operate normally will not have problems so quickly.
Now the No. [-] and No. [-] engines also have problems. In fact, their condition has been quite critical so far.
"Which altitude did you descend to?" asked the captain in charge.Suddenly, the captain in charge thought of one thing: "We can't identify a reliable airspeeder now, how can we fly at the drifting speed?"
After this reminder, the second captain also woke up.That's right, if the plane wants to drift down, it must follow the drifting speed.But now they don't know the airspeed of their plane at all, how can they drift down?
Sure enough, the fault of unreliable airspeed seems to have little effect, but in actual flight, this fault will cause many problems, and it cannot be completed by just a drifting down.
"Also, if it drifts down, how can we be sure that the state of the aircraft is within the limits." The captain in charge continued to add: "There is no chart related to drifting down in the flight chart of unreliable airspeed. We simply don't have the relevant data to refer to."
Both the responsible captain and the second captain could understand the reason why Xu Cang wanted to drift down.In the current situation of power loss, it is unknown whether the plane can survive to Jakarta's Soekarno-Hatta Airport.
Therefore, while the height is still enough, Xu Cang hopes to use the method of drifting down, which has the highest glide ratio, to convert the height into a horizontal displacement as much as possible.
At this time, a fatal problem was actually involved, that is, whether the plane could still fly to Soekarno-Hatta Airport.Before that, the captain in charge was quite confident. After all, the failure of only one engine is not too serious for a 747. The situation is different now.
The calculation of height-to-distance ratio must be taken into account in order to deal with the most extreme cases.
However, the optimal solution now is naturally to let the aircraft drift down to travel a longer distance with the same altitude loss, but they cannot complete this operation at an unreliable airspeed.
Due to the lack of real data reference, the most direct problem is that it is impossible to distinguish whether the aircraft is in an extremely dangerous situation, such as stalling or overspeeding.False overspeed and stall warnings are often accompanied by unreliable airspeed.
However, logically the crew was unable to distinguish between false overspeed and stall warnings.All they can do is climb, cruise, descend and approach according to the specific settings in the flight performance chapter, and there are restrictions on how the aircraft state can be changed.As long as the state of the aircraft is changed according to these restricted methods, then theoretically, the aircraft can be kept within a reasonable speed range, that is, overspeed and stall in this state can be considered false.
However, the limitation of changing the state of the aircraft can also cause a lot of problems.
For example, only the maximum climb thrust can be used when climbing, and the EPR and N1 speed can only be set at a specific altitude and full weight when cruising.It's this restricted way of changing that conflicts with the idea of drifting down, since there are no plane settings for drifting down in the unreliable chart.
If the crew acted on their guts, how would any subsequent warnings on the aircraft's data be dealt with?Forget it, or make corrections according to standard recovery procedures?
When the airspeed cannot be clearly known, how can the crew recover from overspeed or stall?So, this is a dead end.
"However, we are very lucky!" Under the watchful eyes of the captain in charge and the second captain, Xu Cang began to slowly withdraw the throttle, not just to withdraw the problematic No. [-] and No. [-] engines, but to take out the No. No. engine together.
Xu Cang said calmly: "The descent speed of a 75-foot full-weight aircraft below 280 feet is actually about 290 knots, and the descent setting at an unreliable airspeed is one-degree attitude, idle thrust, theoretically formed The speed of 2000 knots, the descent rate is 280 feet per minute. The drifting speed of 290 five knots is basically consistent with the theoretical speed of [-] knots set by the slow car at unreliable airspeed, so for a period of time, we can take care of both of those."
As soon as this remark came out, the responsible captain was immediately stunned.He brought over the checklist, flipped through the charts of unreliable airspeed and drifting quickly, and then took a deep breath: "It's really the same!"
The second captain waved and asked the responsible captain to show him the checklist.As a result, after looking at it, he felt that the three outlooks on life had deviated.Originally, unreliable airspeed and aircraft drifting are completely irrelevant and cannot be both. However, Xu Cang can turn decay into magic and combine the two into one?
This hand alone really shocked the second captain!
Exquisite, it is too exquisite!
So, when Xu Cang closed the throttle, no one of the two captains dared to say anything anymore, they were really convinced.
"However, as the altitude of the aircraft changes, the difference between the two speeds will gradually increase. At that time, we can only follow the flight charts with unreliable airspeeds. If we drift down, we will do our best and obey the destiny." Xu Cang said: "Now we have to descend. If... if we are lucky, we will break through the bottom layer of the volcanic ash cluster in a low-altitude environment. By then, everything will be easy to handle."
Volcanic ash clusters are actually similar to cloud clusters. Their positions are neither too high nor too low. Perhaps as the altitude of the aircraft decreases, the plane can descend directly below the volcanic ash cluster, where the concentration of volcanic ash will be much lower. Perhaps, If they can reach that height, they will have a way to survive in ultra-low-altitude sea-skimming flights.
"I hope!" When Xu Cang started to stop the throttle, the captain in charge directly contacted Jakarta control: "Jakarta control, British Airways 1009!"
"BA 1009, Jakarta control, please tell me!"
"We are now turning off the No. [-] engine, and the No. [-] and No. [-] engines have surge phenomena, and we can no longer maintain the altitude. Now we are returning to Soekarno-Hatta Airport in drifting mode!"
"British Airways 1009, now there is no aircraft conflict below your route, you can descend by yourself." Jakarta control immediately said: "We have received a notice from the Soekarno-Hatta Airport. They measured that the visibility and vertical visibility of the field are both Already below Class I standard."
"What about the second category?" This sentence is not a question from the responsible captain, but from Xu Cang, and it is in English.
Xu Cang's oral English is not very good, but it doesn't mean he can't speak at all. Some simple communication is no problem.
"Engine failure can fly the second category?" The responsible captain was stunned.
Xu Cang actually didn't want to fly like this, because in the second category of operation, the first thing to be promoted in any country is to land with automatic driving.If all countries can be consistent, it means that autopilot landing is the optimal solution for the second type of operation. Manual flight, let alone manual flight when power is damaged is really not a suitable option.
But whenever there is a better choice, Xu Cang will not make such a risky choice.After all, I just learned that Sukarno-Hatta's field was also covered by volcanic ash. If there were other failures during the approach, it would be difficult to handle.
"As long as there is a stable guiding signal." Xu Cang said lightly.
But God seems unwilling to give Xu Cang and the others this option that is already taking risks. Only the Jakarta control said: "The airport is still studying it. The concentration of volcanic ash in this field is increasing rapidly, maybe."
Hearing this, the captain in charge turned pale instantly: "Maybe you can't even meet the standard of the second category?"
"That's right, the runway visual range of this field is now less than 400 meters, and the vertical visibility is between 10 and [-] feet. According to this standard, it meets the second category standard. However, it was released just [-] minutes ago According to the local weather report, the runway visibility is still three kilometers away, and the cloud base height is [-] feet. According to this deterioration trend, the second-class standard of this field will not be satisfied soon.”
Xu Cang's hand holding the steering wheel couldn't help but use his strength. In less than 10 minutes, the weather standard on this field dropped so much. Then it would be impossible for them to return to the Soekarno-Hatta Airport. There are two types of standards.
"What about Singapore Changi Airport?" The responsible airport asked immediately.
In the nearby area, only Soekarno-Hatta Airport and Changi Airport in Singapore can land.At this time, the disadvantage of the 747 in choosing an alternate field is reflected.Due to their large size and extremely long take-off and landing distances, smaller airports cannot meet the landing standards at all, and only large airports can. Therefore, the range they can choose is actually very small.
Singapore Changi International Airport is a well-known large hub in the world. It has three runways and is bigger than Soekarno-Hatta Airport. It is a pretty good extra choice.
However, Changi International Airport is still on the west side of Soekarno-Hatta Airport, which makes the flight time longer, which is actually not friendly to today's power-damaged aircraft.
But compared to Soekarno-Hatta Airport, which can't even meet the second-class meteorological standards, Singapore Changi International Airport is estimated to be relatively better.
However, as soon as this idea came up, the area control side gave a fatal blow: "From what I have learned, Changi International Airport has stopped taking off and landing, and it is very likely that the airport will be closed soon. In fact, Soekarno-Hatta Airport also plans to close the airport, but it has not been officially announced yet because it agreed to receive your alternate landing. "
In fact, it is quite clear when it comes to this point.Kelude Volcano is a huge active volcano, but once this volcano erupts, the scope of its impact is unimaginable.It should be said that even Changi International Airport and Soekarno-Hatta Airport can't stand it now, even if Xu Cang and the others want to risk their troops and land at some smaller airports, it is impossible.
From this point of view, the world is so big that there is no room for them?
Under such circumstances, even if the two captains were on the plane, the atmosphere dropped to freezing point in an instant.The most important thing is that it is still in the development stage of the volcanic ash, not to mention whether they can hover and wait, even if they find some way later, such as hovering over the low-altitude sea, they will definitely not be able to wait for the moment when the volcanic ash dissipates.
On the eve of running out of fuel, the ash situation will only get worse!
Xu Cang didn't let the captain in charge respond, he probably understood what the controller was saying, and he could also clearly see the almost desperate atmosphere in the cockpit.But Xu Cang didn't give up, he had experienced even more desperate and depressed moments, how could he give up lightly?
"What about the three types of blind surrender?" Xu Cang said suddenly.
As soon as this remark came out, not only the two captains next to him, but even the controller on the radio channel were shocked.
Xu Cang didn't care about the reaction of these people: "Can Soekarno-Hatta Airport provide three types of blind landing operations? According to the current development trend, the three types of A and B are estimated to be unable to meet the standards, and only the three types of C operations can Unconditionally satisfied. Does Soekarno-Hatta Airport have the capacity?"
"Xu Cang, do you have the qualifications for the three types of blind landing?" The responsible captain looked at Xu Cang incredulously: "I remember that your CAAC basically doesn't operate the three types of blind landing, right?"
As we all know, blind drop is divided into three standards, namely, one type, two types and three types.The first type is the most common. Generally speaking, the standard runway visual range of type I is not less than 550 meters and the decision height is not less than 60 meters. This is the standard of most ILS systems today.
Once the meteorological standard does not meet the standard of ILS, if the airport has the capability of the second-class equipment and the permission of the bureau, it can further operate the second-class ILS standard, that is, the runway visual range is not less than 350 meters, and the decision height is not less than 30 meters. , the requirements of its meteorological standards are much lower than that of Class I.
However, Class II operations not only have requirements for airports, but also have special requirements for the qualifications of aircraft and crews. It is for this reason that there are actually not many Class II operations.
However, there are three types of standard IDS above the second type.The third category of blind landing is the same as the second category of blind landing, which requires various authorizations and qualifications, so even if you look at the world, there are only a handful of airports that can operate the third category of blind landing. .
Importantly, the three standard IDS itself is also divided into three subcategories, namely A, B and C categories. Category A has the broadest standard, that is, the runway visual range is not less than 200 meters and the decision height is not less than 30 meters.The runway visual range of category B is 50 meters, and the decision height is usually 15 meters, but theoretically it is possible even if the requirement of 15 meters is not met, that is, on the premise of meeting the runway visual range, the vertical visibility is Zero also meets the criteria for Category III B blind drop.
The three types of C blind landing mentioned by Xu Cang are really the so-called "you can't see your fingers", and there is no requirement for runway visual range and vertical visibility.That is to say, the ILS operation of Category III C can also be carried out under extreme conditions where the runway visual range and vertical visibility are both zero.
Category III IDS is the highest level of instrument landing standard that truly surpasses all visibility standards.
However, even the relatively loose Category [-] A standards basically do not operate on the CAAC side.That's right, even if the airport can operate and the weather conditions are satisfied, the airport will not choose to operate the three types of blind landing.
The captain in charge had flown in China for several years. In his memory, it seemed that only certain runways in two or three airports had Type III ILS, and as far as he knew, he had never heard of it.
It was based on this known information that the responsible captain would ask this question.In fact, British Airways can be regarded as an internationally renowned major airline company, and there are very few crew members in British Airways who have three types of blind landing qualifications.
"No!" Xu Cang's answer was quite decisive, and it seemed so natural that the captain in charge even wondered whether the crew qualification for the three types of blind landings was required.
"I have three types of qualifications!" At this moment, the second captain suddenly spoke, which was so shocking that even Xu Cang looked at him involuntarily.
That is a three-category blind landing. Even after 20 years, there are only a handful of airports in China that can operate three-category blind landing.The main reason is that the three types of ILS have too high requirements for the accuracy and stability of the guidance signal, and many airports cannot maintain such a sophisticated instrument landing system.
The captain in charge interjected a sentence at this time: "But the three types of qualifications must be possessed by everyone present, and it is useless to have only one person."
"I'm not talking about this problem." The second captain looked serious: "Actually, the III-C blind landing has not been approved by the International Civil Aviation Organization. In other words, this is just a concept, not applied to actual operations Technology."
"What did you say?" The responsible captain was not as good as the second captain in terms of theoretical knowledge because he had not participated in the three types of IDS qualifications.He knew the three sub-categories of the three-category IDS, but he really didn't expect that the C-category was not approved by the International Civil Aviation Organization.
Perhaps a "true" ILS without runway visual range and vertical visibility requirements is beyond ICAO's perception of landing safety, even though it is technically possible to do so.
"It doesn't matter whether it is approved or not, as long as the Soekarno-Hatta Airport has the ability to implement three types of blind landings. Not being allowed and not being able to fly are not the same meaning." Xu Cang said lightly, as if he had known the three types of C Blind landings are not permitted.
The second captain suddenly changed his face: "You mean, if the Soekarno-Hatta Airport can perform Type III C blind landing, you will violate the regulations?"
"That's right!" Xu Cang answered this question directly, clearly and clearly, without any doubts: "Actually, even if they don't have the signal of Category [-]-C blind landing level, even the signal level of Category [-]-A blind landing is enough to send the plane down." Guided correctly onto the runway!"
"You are violating the rules!" The second captain shouted.
Not to mention the lack of qualifications of the crew, it is hard to say whether the current state of the aircraft can perform a three-category blind landing, and Xu Cang actually wants to use the signal level of a three-category A blind landing instead of a three-category C blind landing signal, which is obviously wrong of.
"If there is a method that does not violate the rules and allows me to land safely, you can give it to me." Xu Cang said coldly.
Just as the two were arguing, the Jakarta control voice rang on the radio: "British Airways 1009, we have received feedback from Soekarno-Hatta Airport that this field has three types of blind landing equipment."
As soon as these words came out, Xu Cang's body tensed up involuntarily, God finally didn't close all the passages for him.
The second captain, who was still arguing about the implementation of the three types of blind landing under such conditions, did not raise any objections, as if he had acquiesced.
"Help us contact Soekarno-Hatta Airport and let it activate the three types of blind landing signals. We still plan to return to this field." Xu Cang directly made a decision and made a final decision.
Now Xu Cang's plan is to quickly descend to a low-altitude environment under the thrust of the slow car. Under the thrust of the slow car, the damage to the engine from the volcanic ash can be minimized.As long as the concentration of volcanic ash is reduced in a low-altitude environment, they may be able to fly normally.Then, maintain a low-altitude flyby to Soekarno-Hatta Airport, and perform three types of blind landing.
It is true that three types of blind landings require autopilot, but Xu Cang is confident that as long as the plane does not have any major problems, he can maintain the navigation accuracy of the plane under the level of autopilot under manual control.
This is why Xu Cang can ignore the rules, as long as he is given a guiding signal, he can land on the runway.
However, Xu Cang has already planned the follow-up flight plan here, but the control side gave them a news that made them feel desperate: "British Airways 1009, Soekarno-Hatta Airport can indeed operate three types of blind landing , but not long ago, the airport's self-inspection found that the blind landing equipment was damaged by volcanic ash, and it is still under maintenance."
These words directly caused the three people in the cockpit to fall into a long silence. Now not only the three types of blind landings, but also the signals of the first types of blind landings are gone.
"How long is it expected to be repaired?" the captain in charge asked.
Regional control said: "We don't have a definite news yet, but it is expected to be more than six hours."
"Six hours." Xu Cang felt as if his heart had been severely pinched, and he was almost out of breath.Six hours, in this environment, they don't know if they can survive for an hour.
"Let's keep the course first!" The captain in charge has no idea now, so he can only apply to keep the course and fly to Soekarno-Hatta Airport, and then make a decision.
"Okay! British Airways 1009, if you need anything, please contact us."
The radio sound stopped, and the cockpit fell into a long silence.In the end, it was the second captain who broke the silence: "The clearance conditions around Soekarno-Hatta Airport are very poor. Without the help of the instrument landing system, it is absolutely impossible to approach."
"Then what should I do?" The captain in charge asked this soul question. There are only two airports that can land. Soekarno-Hatta Airport is not available for blind landing, and Changi International Airport is directly closed.
"What about non-precision approach?" Xu Cang asked, "Is there any non-precision approach at Soekarno-Hatta Airport?"
"There is a VOR/DME approach to runway 27." The captain in charge said, "However, the minimum descent altitude over there is [-] feet above the ground, and we can't go down to the last [-] feet."
The meteorological standard requirements for non-precision and precision approaches are much higher than those for precision approaches. The decision height for a type of blind landing is only [-] feet, and the minimum descent altitude for VOR/DME approaches is fully doubled. many.
In the logic of the responsible captain, even a type of ILS is not standard enough, let alone a non-precision approach.
However, Xu Cang did not pin his hopes on the non-precision approach, he just asked: "Is there any angle between the course of the VOR/DME approach and the extension line of the runway?"
Generally speaking, the final course of VOR/DME approach coincides with the runway extension line, but in the case of some external reasons, the final course will have a small angle with the runway extension line.
In fact, in some extreme cases, the localizer of an ILS can have an included angle with the runway extension, let alone a non-precision approach.
"That's not the case. The VOR fifth side of runway 27 is at the same height as the runway extension line, both at 271 degrees." The captain in charge suddenly felt a little strange when he said this: "Xu Cang, what do you want to do? Soekarno-Hatta Airport has very poor clearance conditions on the final side, and you must not land blindly. Sometimes, even under the guidance of blind landing, if the descent rate is not well grasped, the terrain warning will sound."
After the captain in charge finished speaking, the cockpit fell into an eerie silence again.To be honest, the current situation is really quite clear. Their range of choices is very small. One is Soekarno-Hatta Airport, one is Changi International Airport, one can land but cannot, and one simply closed the airport.
"To be honest, even if Changi Airport is not closed, we probably won't be able to fly there." The captain in charge lowered his head and said absentmindedly: "There is a Seru bridge between Soekarno-Hatta Airport and Changi International Airport. Meihuo, our current situation seems to be irreversible."
If the plane continues to fly in the volcanic ash, it is very likely that even the Soekarno-Hatta Airport will not be able to fly.The only thing they can count on is a reduced concentration of volcanic ash at low altitudes.
However, Serume Volcano is close to 4000 meters above sea level. If you want to climb over this mountain, you have to go up to an altitude of more than [-] feet to be considered relatively safe.But at this altitude, the plane will inevitably enter the volcanic ash again, and this altitude is likely to be the area with the highest concentration of volcanic ash.
If they want to forcibly cross the Serume volcano, there is a high possibility that they will lose all power in the volcanic ash and then crash into the mountainous area.
"Xu Cang." The captain in charge said suddenly: "I heard that you completed a forced landing at sea not long ago!"
"What, a forced landing at sea?" At this moment, the second captain almost jumped up: "You flew a forced landing at sea? How is it possible that you are so young and can complete a forced landing at sea and still succeed?"
Ditching at sea is a difficult problem recognized by the world, the variables are too great, and this young man in his 20s can actually complete the ditching at sea?
You know, in foreign countries, Xu Cang's age can only be called Baby Pilot, but such a baby pilot has such a legendary experience.
However, the captain in charge didn't care about the reaction of the second captain, but said seriously: "In the area we can fly to, there are only those two airports where the 747 can land. Now those two airports cannot land. Then we will not land on land, we will fall into the sea!?"
The second captain was shocked by the responsible captain's words, even more shocked than Xu Cang's forced landing at sea just now: "You mean, forced landing in the Pacific Ocean?"
"Xu Cang, you have a successful experience!" The captain in charge is truly extraordinary: "I don't want to pin my hopes on some illusory things, but I am willing to believe in you."
Xu Cang was startled, he didn't speak, didn't refuse, and didn't agree.In fact, Xu Cang had thought about this possibility before the captain in charge made this suggestion.
The land restricts them too much, but the vast Pacific Ocean has a lot to do.However, it is now late at night, unlike the previous forced landing in the coastal area of Qizhou, at the last moment, the rising sun gave Xu Cang one last chance to make corrections, otherwise his direction of falling into the water would be completely opposite.
However, the current time is completely wrong, there are at least eight hours before sunrise, so they still have to wait in the sky for eight hours.And, there is another important question.
Last time in Qizhou, he could precisely control the location of the plane's forced landing at sea, which is very convenient for sea rescue.However, this time, Xu Cang was unable to choose a suitable area for the forced landing due to his ignorance of the surrounding terrain.
That's right, the Pacific Ocean is huge, but if they land a little farther away, in the deep night and the open sea, even if they can fall, will they survive until rescue arrives?
Just as Xu Cang was hesitating, a black ink dot fell on the windshield with a bang.
The dull voice seemed to stir Xu Cang's nerves. He cast his gaze away, and saw more and more ink dots appearing on the windshield. In an instant, these ink dots merged into a stream and flowed down the windshield. .
"It's raining?" Xu Cang frowned, it was clearly rain mixed with volcanic ash dripping onto the fuselage.
If it rains, the impact on the aircraft is not too great, but suddenly, the main warning light of the aircraft suddenly lights up, according to the display, it is a failure of the air source system.
Xu Cang and the captain in charge looked up at the same time, only to see that the light of the No. [-] component was on.
"The components are on?" Xu Cang felt a little irritable. When people are unlucky, misfortunes never come singly.Fortunately, the 747 has three sets of components, and the failure of just one component will not affect too much.
"Shall I do a checklist?" asked the captain in charge.
Xu Cang nodded: "You do it!"
"Okay!" The captain in charge didn't even open the checklist, but started it directly. Of course, this is not a compliant move, but at this time, even the relatively rigid second captain didn't ask any questions, because he I was thinking about the possibility of an forced landing in the Pacific Ocean proposed by the responsible captain just now.
However, it seems that there is no room for thinking now, and they seem to have no other choices.
The responsible captain is quite familiar with the component checklist, and this checklist is often practiced during training.After confirming that the switch for adjusting the air was opened, the captain in charge turned the control selector of the No. [-] component to position A, and then pressed the component reset switch.
Soon, the component's fault information directly became blank, which was considered to have eliminated the fault, and it seemed to be just a small problem.
Xu Cang didn't pay close attention to the action of the responsible captain, but he saw that the malfunction light went out, so he didn't pay attention to it any more.Suddenly, Xu Cang saw a little liquid seeping from the lower right corner of the windshield.
He froze for a moment, stretched out his hand and pointed his finger at the lower right corner of the windshield, and felt a wet feeling at his fingertips.
The captain in charge also noticed Xu Cang's movements, and came closer: "What's the matter? Hmm? Why is there water in the inner layer, is the fog condensed? No! That's seeping in from the outside?"
"Rainwater seeped into the inner layer through the cracks in the outer windshield, but why is the inner glass so poorly sealed?" Xu Cang just finished speaking, and the main warning light came on again. Looking at the prompt, it was still the air source system. Fault.
Perhaps because of the previous experience, Xu Cang first looked at the component lights, and as expected, the No. [-] component light that had just been reset turned on again.
"Turn the control selector to B!" Xu Cang said directly.
The captain in charge nodded, without further ado, he directly turned the control selector of the No. [-] component to B, and then pressed the reset button.
However, the failure information of the No. [-] component did not disappear this time. At the same time, after a short wait, the No. [-] and No. [-] components also turned on the fault lights.
"This!" The captain in charge was taken aback by this, and immediately looked at the pressurization panel, and found that there was no problem with the pressurization of the aircraft for the time being.But if the three components are allowed to fail, it is foreseeable that the aircraft will have problems with pressurization.
"How come all three components are broken?" This was the first time the second captain had seen such a situation.
He has seen one component failure or two component failures. How can all three components fail?This probability is too small.
If the probability of something is so small that it is almost impossible, then it is not a matter of probability, but some other problem that leads to the inevitable occurrence of this failure.
"Could it be the reason for the bleed air?" Xu Cang turned his head and pointed to the wing anti-ice switch: "Turn that off and see!"
"Huh?" The captain in charge didn't understand Xu Cang's motives at first, but he was the captain anyway, so he could quickly remember the reason.
The bleed air of the components depends on the engine. In a high-altitude environment, the air content is already low. At this moment, Xu Cang put all the engines at idle thrust.In this case, the amount of bleed air that the air source system can obtain through the engine is not much.Also, wing anti-icing consumes a lot of bleed air, so there is very little bleed air available to the three components.
In this way, when a very small amount of bleed air is available, the components have to undertake their own pressurization function, which is a bit like letting the components eat grass and milk, and the burden on the components will increase in a short time. Finally overwhelmed and jumped away.
Having figured out this section, the captain in charge immediately turned off the wing anti-ice switches.However, after waiting for a few seconds, all components were reset, and soon all three component lights went out.
"Sure enough, the bleed air is not enough!" The captain in charge breathed a sigh of relief. If there is a problem with the pressurization system, it will take a lot of trouble: "Xu Cang, fortunately, you react quickly!"
Really, the responsible captain is exhausted by now.
Volcanic ash caused too many cascading problems.The presence of volcanic ash likely blocked the pitot tubes, resulting in unreliable airspeed, and the buildup of static electricity from rubbing against the fuselage affected the aircraft's electronic systems, such as the flight management computer.Among them, the unreliable airspeed has the most extended problems. It is precisely because of the existence of unreliable airspeed that it is necessary to open the wing anti-icing switch, and at the same time, the throttle needs to be received by the idle thrust when descending. Insufficient bleed air eventually caused problems with the components.
The crack on the outer layer of the right front windshield was also due to the impact of a larger piece of volcanic rock. As for the sealing problem of the inner windshield, the captain in charge did not know whether it was also related to volcanic ash.
It is precisely because of these problems and failures one after another that all pilots are so afraid of entering the volcanic ash.
However, no matter what, the problem of the component was finally solved.The captain in charge was a little more relaxed just now, and wanted to talk about the possibility of a forced landing at sea.Suddenly, the plane began to vibrate with extremely high frequency and finely, without warning, even the steering wheel that Xu Cang was holding was vibrating left and right.
The discussion of ditching at sea was quickly interrupted by this sudden situation.The vibration of the steering wheel was so violent that Xu Cang couldn't hold on to it.Moreover, the buffeting of the steering wheel is only one aspect, and even the aircraft seems to be vibrating violently.
"Stick shaking?" The captain in charge was stunned: "That's not right! Stall stick shaking isn't like that!"
The first thing a pilot thinks of when the cockpit vibrates is stall shake, which is almost engraved in the pilot's genes.However, every time the cockpit is prepared, the pilot has to test the stall shaker. Pilots are all too aware of what kind of warning the aircraft stick shaker is and what it looks like.
Now the steering wheel is indeed vibrating, but it is still somewhat different from the stall shaker.Moreover, now Xu Cang is setting up the plane according to the chart in the flight performance, and there is no possibility of stalling.
However, compared to the vibration of the steering wheel, Xu Cang suddenly felt that there was something wrong with the plane's descent rate.Because according to the flight chart, under the current attitude and idle thrust, the aircraft's descent rate should be in the early [-] feet per minute, but now it is getting bigger and bigger, almost reaching [-] feet per minute. This gap A little big.
"The descent rate doesn't seem right!" The second captain also discovered this problem.
Xu Cang hesitated, and lightly brought down the rod with his right hand. However, he suddenly felt that the force of the rod was unbelievably light.
"How could this be? Why is the force of the pitch bar so light?" Xu Cang was taken aback, unable to figure out why this happened.
"What did you say?" The captain in charge also took the downstick with his left hand, and he pulled out a long length quite easily, but reflected on the plane, the plane's descent rate increased instead of decreasing. In an instant, it broke through the three thousand feet per minute mark.
Such an abnormal phenomenon directly stunned the responsible captain and the second captain. How could there be a stick to accelerate the plane's descent?This is totally unreasonable!
However, Xu Cang's reaction was so fast, he immediately shouted: "No, it's turbulent flow!"
Then, Xu Cang no longer took the stick, but suddenly pushed the steering wheel forward, and in an instant, the attitude of the aircraft was reduced to minus one degree.
"What are you doing!" The second captain shouted immediately.
Xu Cang's thrusting action directly pushed the plane's descent rate to a rate exceeding [-] feet per minute, and the plane was diving down at an unimaginable speed.
"It's stalled, the plane is stalled!" Xu Cang shouted, "The plane has entered a deep stall!"
"Deep stall, how is it possible?" The responsible captain did not react.But if it's a deep stall, that does explain everything.Under the condition of deep stall, the rudder surface of the aircraft is full of turbulence, and the effect of the rudder surface is almost zero. It is for this reason that when Xu Cang controls the aircraft to pitch, he feels that the stick force is very small.
Because at this moment on the elevator, the airflow has been separated from the rudder surface, the reaction to the stick force is naturally quite small.
The action of the responsible captain and Xu Cang with the stick undoubtedly increased the angle of attack of the plane.The underlying logic of the stall is that the angle of attack of the aircraft is greater than the critical angle of attack, so the procedure for recovering from the aircraft is to reduce the angle of attack.In this way, increasing the angle of attack will increase the stall situation of the aircraft, and the aircraft will naturally accelerate to fall.
However, the problem is that the plane was still fine not long ago, why did it suddenly change from a normal state to a deep stall? This change is too fast?
Suddenly, the responsible captain realized that the only change before that was to turn off the wing anti-ice switches.
"Is it icing?" the captain in charge murmured.
"Freezing rain, it's freezing rain outside, freezing rain that will freeze as soon as it touches the fuselage!" Xu Cang shouted: "The engine anti-icing and wing anti-icing are all turned on!"
"What about the supercharging?" The second captain shouted: "Once the wing anti-icing is turned on, the supercharging will be gone! At this altitude, we can't survive without supercharging!"
At this moment, the outside is full of volcanic ash and cold water vapor.There are no components for pressurization and air circulation, and it is estimated that there will be a large number of casualties among the people in the cabin. How can this be accepted by the second captain.
In his opinion, the angle of attack of the plane is already very small now, and it should be possible to change it.
However, at this moment, Xu Cang suddenly felt that the thrust force of the steering wheel had become extremely weak. With almost no force, he pushed the steering wheel to the end, but the attitude of the plane did not change.
"The effect of the elevator and rudder surface has completely disappeared!?" Xu Cang's face turned pale: "Stall, it can't be changed!"
It's not that I want to procrastinate, but the chain reaction caused by the volcanic ash is much more complicated than the relatively single failure encountered before. The aircraft will fail in various systems. In order to ensure professionalism, we can only use a slightly longer one. Take into account the space.
Of course, I can't be considered a professional, I just try to get closer to the top.
(End of this chapter)
Those two completely different surge sounds were constantly hitting Xu Cang's heart like heavy hammers.
For a four-engine aircraft like the 747, the impact of one engine failure is not as great as for a twin-engine aircraft.It is precisely because of the existence of this huge margin that the four-engine aircraft does not need to comply with the ETOPS standard.
However, if the second and third engines also stalled, the situation would be completely different.
"It started to surge again?" The responsible captain also heard the sound of surge, and his eyes drifted away from the N1 speed for a moment.Sure enough, the N1 speed of the No. [-] and No. [-] engines has begun to become unstable, which is also one of the signs of engine surge.
"Tell Jakarta control that we will carry out single-engine drifting." Xu Cang said immediately.
The second captain was taken aback, obviously puzzled by Xu Cang's way of drifting down: "Don't you keep the altitude? Isn't the volcanic ash thicker when you go down?"
"There are only three engines left now, and two of them have surged, and they have to descend if they don't descend." After that, he needs to reduce the thrust of the No. [-] and No. [-] engines, at least to ensure that they will not stall.Once turned off in this environment, it is likely that it will not be restarted.
And as long as the No. [-] and No. [-] engines are operated with reduced thrust, most of the power demand will be put on the No. [-] engine, which is obviously beyond the capacity of the No. [-] engine.
What's more, running in the volcanic ash area, high thrust and high speed are more likely to cause damage to the engine. Xu Cang is not willing to have problems with the only No. [-] engine that is still running normally.
The captain in charge thought for a moment, then nodded heavily.Before that, the three engines were normal, and it didn't matter if one engine was scrapped.If it is still strong now, there is likely to be only one engine left, and it is unknown whether this engine can last.
In the final analysis, it was too reckless to cut the No. [-] engine by myself.If it can be kept above [-] feet, it is almost at the upper edge of the volcanic ash area, and the concentration of volcanic ash is not high.The remaining three engines that can still operate normally will not have problems so quickly.
Now the No. [-] and No. [-] engines also have problems. In fact, their condition has been quite critical so far.
"Which altitude did you descend to?" asked the captain in charge.Suddenly, the captain in charge thought of one thing: "We can't identify a reliable airspeeder now, how can we fly at the drifting speed?"
After this reminder, the second captain also woke up.That's right, if the plane wants to drift down, it must follow the drifting speed.But now they don't know the airspeed of their plane at all, how can they drift down?
Sure enough, the fault of unreliable airspeed seems to have little effect, but in actual flight, this fault will cause many problems, and it cannot be completed by just a drifting down.
"Also, if it drifts down, how can we be sure that the state of the aircraft is within the limits." The captain in charge continued to add: "There is no chart related to drifting down in the flight chart of unreliable airspeed. We simply don't have the relevant data to refer to."
Both the responsible captain and the second captain could understand the reason why Xu Cang wanted to drift down.In the current situation of power loss, it is unknown whether the plane can survive to Jakarta's Soekarno-Hatta Airport.
Therefore, while the height is still enough, Xu Cang hopes to use the method of drifting down, which has the highest glide ratio, to convert the height into a horizontal displacement as much as possible.
At this time, a fatal problem was actually involved, that is, whether the plane could still fly to Soekarno-Hatta Airport.Before that, the captain in charge was quite confident. After all, the failure of only one engine is not too serious for a 747. The situation is different now.
The calculation of height-to-distance ratio must be taken into account in order to deal with the most extreme cases.
However, the optimal solution now is naturally to let the aircraft drift down to travel a longer distance with the same altitude loss, but they cannot complete this operation at an unreliable airspeed.
Due to the lack of real data reference, the most direct problem is that it is impossible to distinguish whether the aircraft is in an extremely dangerous situation, such as stalling or overspeeding.False overspeed and stall warnings are often accompanied by unreliable airspeed.
However, logically the crew was unable to distinguish between false overspeed and stall warnings.All they can do is climb, cruise, descend and approach according to the specific settings in the flight performance chapter, and there are restrictions on how the aircraft state can be changed.As long as the state of the aircraft is changed according to these restricted methods, then theoretically, the aircraft can be kept within a reasonable speed range, that is, overspeed and stall in this state can be considered false.
However, the limitation of changing the state of the aircraft can also cause a lot of problems.
For example, only the maximum climb thrust can be used when climbing, and the EPR and N1 speed can only be set at a specific altitude and full weight when cruising.It's this restricted way of changing that conflicts with the idea of drifting down, since there are no plane settings for drifting down in the unreliable chart.
If the crew acted on their guts, how would any subsequent warnings on the aircraft's data be dealt with?Forget it, or make corrections according to standard recovery procedures?
When the airspeed cannot be clearly known, how can the crew recover from overspeed or stall?So, this is a dead end.
"However, we are very lucky!" Under the watchful eyes of the captain in charge and the second captain, Xu Cang began to slowly withdraw the throttle, not just to withdraw the problematic No. [-] and No. [-] engines, but to take out the No. No. engine together.
Xu Cang said calmly: "The descent speed of a 75-foot full-weight aircraft below 280 feet is actually about 290 knots, and the descent setting at an unreliable airspeed is one-degree attitude, idle thrust, theoretically formed The speed of 2000 knots, the descent rate is 280 feet per minute. The drifting speed of 290 five knots is basically consistent with the theoretical speed of [-] knots set by the slow car at unreliable airspeed, so for a period of time, we can take care of both of those."
As soon as this remark came out, the responsible captain was immediately stunned.He brought over the checklist, flipped through the charts of unreliable airspeed and drifting quickly, and then took a deep breath: "It's really the same!"
The second captain waved and asked the responsible captain to show him the checklist.As a result, after looking at it, he felt that the three outlooks on life had deviated.Originally, unreliable airspeed and aircraft drifting are completely irrelevant and cannot be both. However, Xu Cang can turn decay into magic and combine the two into one?
This hand alone really shocked the second captain!
Exquisite, it is too exquisite!
So, when Xu Cang closed the throttle, no one of the two captains dared to say anything anymore, they were really convinced.
"However, as the altitude of the aircraft changes, the difference between the two speeds will gradually increase. At that time, we can only follow the flight charts with unreliable airspeeds. If we drift down, we will do our best and obey the destiny." Xu Cang said: "Now we have to descend. If... if we are lucky, we will break through the bottom layer of the volcanic ash cluster in a low-altitude environment. By then, everything will be easy to handle."
Volcanic ash clusters are actually similar to cloud clusters. Their positions are neither too high nor too low. Perhaps as the altitude of the aircraft decreases, the plane can descend directly below the volcanic ash cluster, where the concentration of volcanic ash will be much lower. Perhaps, If they can reach that height, they will have a way to survive in ultra-low-altitude sea-skimming flights.
"I hope!" When Xu Cang started to stop the throttle, the captain in charge directly contacted Jakarta control: "Jakarta control, British Airways 1009!"
"BA 1009, Jakarta control, please tell me!"
"We are now turning off the No. [-] engine, and the No. [-] and No. [-] engines have surge phenomena, and we can no longer maintain the altitude. Now we are returning to Soekarno-Hatta Airport in drifting mode!"
"British Airways 1009, now there is no aircraft conflict below your route, you can descend by yourself." Jakarta control immediately said: "We have received a notice from the Soekarno-Hatta Airport. They measured that the visibility and vertical visibility of the field are both Already below Class I standard."
"What about the second category?" This sentence is not a question from the responsible captain, but from Xu Cang, and it is in English.
Xu Cang's oral English is not very good, but it doesn't mean he can't speak at all. Some simple communication is no problem.
"Engine failure can fly the second category?" The responsible captain was stunned.
Xu Cang actually didn't want to fly like this, because in the second category of operation, the first thing to be promoted in any country is to land with automatic driving.If all countries can be consistent, it means that autopilot landing is the optimal solution for the second type of operation. Manual flight, let alone manual flight when power is damaged is really not a suitable option.
But whenever there is a better choice, Xu Cang will not make such a risky choice.After all, I just learned that Sukarno-Hatta's field was also covered by volcanic ash. If there were other failures during the approach, it would be difficult to handle.
"As long as there is a stable guiding signal." Xu Cang said lightly.
But God seems unwilling to give Xu Cang and the others this option that is already taking risks. Only the Jakarta control said: "The airport is still studying it. The concentration of volcanic ash in this field is increasing rapidly, maybe."
Hearing this, the captain in charge turned pale instantly: "Maybe you can't even meet the standard of the second category?"
"That's right, the runway visual range of this field is now less than 400 meters, and the vertical visibility is between 10 and [-] feet. According to this standard, it meets the second category standard. However, it was released just [-] minutes ago According to the local weather report, the runway visibility is still three kilometers away, and the cloud base height is [-] feet. According to this deterioration trend, the second-class standard of this field will not be satisfied soon.”
Xu Cang's hand holding the steering wheel couldn't help but use his strength. In less than 10 minutes, the weather standard on this field dropped so much. Then it would be impossible for them to return to the Soekarno-Hatta Airport. There are two types of standards.
"What about Singapore Changi Airport?" The responsible airport asked immediately.
In the nearby area, only Soekarno-Hatta Airport and Changi Airport in Singapore can land.At this time, the disadvantage of the 747 in choosing an alternate field is reflected.Due to their large size and extremely long take-off and landing distances, smaller airports cannot meet the landing standards at all, and only large airports can. Therefore, the range they can choose is actually very small.
Singapore Changi International Airport is a well-known large hub in the world. It has three runways and is bigger than Soekarno-Hatta Airport. It is a pretty good extra choice.
However, Changi International Airport is still on the west side of Soekarno-Hatta Airport, which makes the flight time longer, which is actually not friendly to today's power-damaged aircraft.
But compared to Soekarno-Hatta Airport, which can't even meet the second-class meteorological standards, Singapore Changi International Airport is estimated to be relatively better.
However, as soon as this idea came up, the area control side gave a fatal blow: "From what I have learned, Changi International Airport has stopped taking off and landing, and it is very likely that the airport will be closed soon. In fact, Soekarno-Hatta Airport also plans to close the airport, but it has not been officially announced yet because it agreed to receive your alternate landing. "
In fact, it is quite clear when it comes to this point.Kelude Volcano is a huge active volcano, but once this volcano erupts, the scope of its impact is unimaginable.It should be said that even Changi International Airport and Soekarno-Hatta Airport can't stand it now, even if Xu Cang and the others want to risk their troops and land at some smaller airports, it is impossible.
From this point of view, the world is so big that there is no room for them?
Under such circumstances, even if the two captains were on the plane, the atmosphere dropped to freezing point in an instant.The most important thing is that it is still in the development stage of the volcanic ash, not to mention whether they can hover and wait, even if they find some way later, such as hovering over the low-altitude sea, they will definitely not be able to wait for the moment when the volcanic ash dissipates.
On the eve of running out of fuel, the ash situation will only get worse!
Xu Cang didn't let the captain in charge respond, he probably understood what the controller was saying, and he could also clearly see the almost desperate atmosphere in the cockpit.But Xu Cang didn't give up, he had experienced even more desperate and depressed moments, how could he give up lightly?
"What about the three types of blind surrender?" Xu Cang said suddenly.
As soon as this remark came out, not only the two captains next to him, but even the controller on the radio channel were shocked.
Xu Cang didn't care about the reaction of these people: "Can Soekarno-Hatta Airport provide three types of blind landing operations? According to the current development trend, the three types of A and B are estimated to be unable to meet the standards, and only the three types of C operations can Unconditionally satisfied. Does Soekarno-Hatta Airport have the capacity?"
"Xu Cang, do you have the qualifications for the three types of blind landing?" The responsible captain looked at Xu Cang incredulously: "I remember that your CAAC basically doesn't operate the three types of blind landing, right?"
As we all know, blind drop is divided into three standards, namely, one type, two types and three types.The first type is the most common. Generally speaking, the standard runway visual range of type I is not less than 550 meters and the decision height is not less than 60 meters. This is the standard of most ILS systems today.
Once the meteorological standard does not meet the standard of ILS, if the airport has the capability of the second-class equipment and the permission of the bureau, it can further operate the second-class ILS standard, that is, the runway visual range is not less than 350 meters, and the decision height is not less than 30 meters. , the requirements of its meteorological standards are much lower than that of Class I.
However, Class II operations not only have requirements for airports, but also have special requirements for the qualifications of aircraft and crews. It is for this reason that there are actually not many Class II operations.
However, there are three types of standard IDS above the second type.The third category of blind landing is the same as the second category of blind landing, which requires various authorizations and qualifications, so even if you look at the world, there are only a handful of airports that can operate the third category of blind landing. .
Importantly, the three standard IDS itself is also divided into three subcategories, namely A, B and C categories. Category A has the broadest standard, that is, the runway visual range is not less than 200 meters and the decision height is not less than 30 meters.The runway visual range of category B is 50 meters, and the decision height is usually 15 meters, but theoretically it is possible even if the requirement of 15 meters is not met, that is, on the premise of meeting the runway visual range, the vertical visibility is Zero also meets the criteria for Category III B blind drop.
The three types of C blind landing mentioned by Xu Cang are really the so-called "you can't see your fingers", and there is no requirement for runway visual range and vertical visibility.That is to say, the ILS operation of Category III C can also be carried out under extreme conditions where the runway visual range and vertical visibility are both zero.
Category III IDS is the highest level of instrument landing standard that truly surpasses all visibility standards.
However, even the relatively loose Category [-] A standards basically do not operate on the CAAC side.That's right, even if the airport can operate and the weather conditions are satisfied, the airport will not choose to operate the three types of blind landing.
The captain in charge had flown in China for several years. In his memory, it seemed that only certain runways in two or three airports had Type III ILS, and as far as he knew, he had never heard of it.
It was based on this known information that the responsible captain would ask this question.In fact, British Airways can be regarded as an internationally renowned major airline company, and there are very few crew members in British Airways who have three types of blind landing qualifications.
"No!" Xu Cang's answer was quite decisive, and it seemed so natural that the captain in charge even wondered whether the crew qualification for the three types of blind landings was required.
"I have three types of qualifications!" At this moment, the second captain suddenly spoke, which was so shocking that even Xu Cang looked at him involuntarily.
That is a three-category blind landing. Even after 20 years, there are only a handful of airports in China that can operate three-category blind landing.The main reason is that the three types of ILS have too high requirements for the accuracy and stability of the guidance signal, and many airports cannot maintain such a sophisticated instrument landing system.
The captain in charge interjected a sentence at this time: "But the three types of qualifications must be possessed by everyone present, and it is useless to have only one person."
"I'm not talking about this problem." The second captain looked serious: "Actually, the III-C blind landing has not been approved by the International Civil Aviation Organization. In other words, this is just a concept, not applied to actual operations Technology."
"What did you say?" The responsible captain was not as good as the second captain in terms of theoretical knowledge because he had not participated in the three types of IDS qualifications.He knew the three sub-categories of the three-category IDS, but he really didn't expect that the C-category was not approved by the International Civil Aviation Organization.
Perhaps a "true" ILS without runway visual range and vertical visibility requirements is beyond ICAO's perception of landing safety, even though it is technically possible to do so.
"It doesn't matter whether it is approved or not, as long as the Soekarno-Hatta Airport has the ability to implement three types of blind landings. Not being allowed and not being able to fly are not the same meaning." Xu Cang said lightly, as if he had known the three types of C Blind landings are not permitted.
The second captain suddenly changed his face: "You mean, if the Soekarno-Hatta Airport can perform Type III C blind landing, you will violate the regulations?"
"That's right!" Xu Cang answered this question directly, clearly and clearly, without any doubts: "Actually, even if they don't have the signal of Category [-]-C blind landing level, even the signal level of Category [-]-A blind landing is enough to send the plane down." Guided correctly onto the runway!"
"You are violating the rules!" The second captain shouted.
Not to mention the lack of qualifications of the crew, it is hard to say whether the current state of the aircraft can perform a three-category blind landing, and Xu Cang actually wants to use the signal level of a three-category A blind landing instead of a three-category C blind landing signal, which is obviously wrong of.
"If there is a method that does not violate the rules and allows me to land safely, you can give it to me." Xu Cang said coldly.
Just as the two were arguing, the Jakarta control voice rang on the radio: "British Airways 1009, we have received feedback from Soekarno-Hatta Airport that this field has three types of blind landing equipment."
As soon as these words came out, Xu Cang's body tensed up involuntarily, God finally didn't close all the passages for him.
The second captain, who was still arguing about the implementation of the three types of blind landing under such conditions, did not raise any objections, as if he had acquiesced.
"Help us contact Soekarno-Hatta Airport and let it activate the three types of blind landing signals. We still plan to return to this field." Xu Cang directly made a decision and made a final decision.
Now Xu Cang's plan is to quickly descend to a low-altitude environment under the thrust of the slow car. Under the thrust of the slow car, the damage to the engine from the volcanic ash can be minimized.As long as the concentration of volcanic ash is reduced in a low-altitude environment, they may be able to fly normally.Then, maintain a low-altitude flyby to Soekarno-Hatta Airport, and perform three types of blind landing.
It is true that three types of blind landings require autopilot, but Xu Cang is confident that as long as the plane does not have any major problems, he can maintain the navigation accuracy of the plane under the level of autopilot under manual control.
This is why Xu Cang can ignore the rules, as long as he is given a guiding signal, he can land on the runway.
However, Xu Cang has already planned the follow-up flight plan here, but the control side gave them a news that made them feel desperate: "British Airways 1009, Soekarno-Hatta Airport can indeed operate three types of blind landing , but not long ago, the airport's self-inspection found that the blind landing equipment was damaged by volcanic ash, and it is still under maintenance."
These words directly caused the three people in the cockpit to fall into a long silence. Now not only the three types of blind landings, but also the signals of the first types of blind landings are gone.
"How long is it expected to be repaired?" the captain in charge asked.
Regional control said: "We don't have a definite news yet, but it is expected to be more than six hours."
"Six hours." Xu Cang felt as if his heart had been severely pinched, and he was almost out of breath.Six hours, in this environment, they don't know if they can survive for an hour.
"Let's keep the course first!" The captain in charge has no idea now, so he can only apply to keep the course and fly to Soekarno-Hatta Airport, and then make a decision.
"Okay! British Airways 1009, if you need anything, please contact us."
The radio sound stopped, and the cockpit fell into a long silence.In the end, it was the second captain who broke the silence: "The clearance conditions around Soekarno-Hatta Airport are very poor. Without the help of the instrument landing system, it is absolutely impossible to approach."
"Then what should I do?" The captain in charge asked this soul question. There are only two airports that can land. Soekarno-Hatta Airport is not available for blind landing, and Changi International Airport is directly closed.
"What about non-precision approach?" Xu Cang asked, "Is there any non-precision approach at Soekarno-Hatta Airport?"
"There is a VOR/DME approach to runway 27." The captain in charge said, "However, the minimum descent altitude over there is [-] feet above the ground, and we can't go down to the last [-] feet."
The meteorological standard requirements for non-precision and precision approaches are much higher than those for precision approaches. The decision height for a type of blind landing is only [-] feet, and the minimum descent altitude for VOR/DME approaches is fully doubled. many.
In the logic of the responsible captain, even a type of ILS is not standard enough, let alone a non-precision approach.
However, Xu Cang did not pin his hopes on the non-precision approach, he just asked: "Is there any angle between the course of the VOR/DME approach and the extension line of the runway?"
Generally speaking, the final course of VOR/DME approach coincides with the runway extension line, but in the case of some external reasons, the final course will have a small angle with the runway extension line.
In fact, in some extreme cases, the localizer of an ILS can have an included angle with the runway extension, let alone a non-precision approach.
"That's not the case. The VOR fifth side of runway 27 is at the same height as the runway extension line, both at 271 degrees." The captain in charge suddenly felt a little strange when he said this: "Xu Cang, what do you want to do? Soekarno-Hatta Airport has very poor clearance conditions on the final side, and you must not land blindly. Sometimes, even under the guidance of blind landing, if the descent rate is not well grasped, the terrain warning will sound."
After the captain in charge finished speaking, the cockpit fell into an eerie silence again.To be honest, the current situation is really quite clear. Their range of choices is very small. One is Soekarno-Hatta Airport, one is Changi International Airport, one can land but cannot, and one simply closed the airport.
"To be honest, even if Changi Airport is not closed, we probably won't be able to fly there." The captain in charge lowered his head and said absentmindedly: "There is a Seru bridge between Soekarno-Hatta Airport and Changi International Airport. Meihuo, our current situation seems to be irreversible."
If the plane continues to fly in the volcanic ash, it is very likely that even the Soekarno-Hatta Airport will not be able to fly.The only thing they can count on is a reduced concentration of volcanic ash at low altitudes.
However, Serume Volcano is close to 4000 meters above sea level. If you want to climb over this mountain, you have to go up to an altitude of more than [-] feet to be considered relatively safe.But at this altitude, the plane will inevitably enter the volcanic ash again, and this altitude is likely to be the area with the highest concentration of volcanic ash.
If they want to forcibly cross the Serume volcano, there is a high possibility that they will lose all power in the volcanic ash and then crash into the mountainous area.
"Xu Cang." The captain in charge said suddenly: "I heard that you completed a forced landing at sea not long ago!"
"What, a forced landing at sea?" At this moment, the second captain almost jumped up: "You flew a forced landing at sea? How is it possible that you are so young and can complete a forced landing at sea and still succeed?"
Ditching at sea is a difficult problem recognized by the world, the variables are too great, and this young man in his 20s can actually complete the ditching at sea?
You know, in foreign countries, Xu Cang's age can only be called Baby Pilot, but such a baby pilot has such a legendary experience.
However, the captain in charge didn't care about the reaction of the second captain, but said seriously: "In the area we can fly to, there are only those two airports where the 747 can land. Now those two airports cannot land. Then we will not land on land, we will fall into the sea!?"
The second captain was shocked by the responsible captain's words, even more shocked than Xu Cang's forced landing at sea just now: "You mean, forced landing in the Pacific Ocean?"
"Xu Cang, you have a successful experience!" The captain in charge is truly extraordinary: "I don't want to pin my hopes on some illusory things, but I am willing to believe in you."
Xu Cang was startled, he didn't speak, didn't refuse, and didn't agree.In fact, Xu Cang had thought about this possibility before the captain in charge made this suggestion.
The land restricts them too much, but the vast Pacific Ocean has a lot to do.However, it is now late at night, unlike the previous forced landing in the coastal area of Qizhou, at the last moment, the rising sun gave Xu Cang one last chance to make corrections, otherwise his direction of falling into the water would be completely opposite.
However, the current time is completely wrong, there are at least eight hours before sunrise, so they still have to wait in the sky for eight hours.And, there is another important question.
Last time in Qizhou, he could precisely control the location of the plane's forced landing at sea, which is very convenient for sea rescue.However, this time, Xu Cang was unable to choose a suitable area for the forced landing due to his ignorance of the surrounding terrain.
That's right, the Pacific Ocean is huge, but if they land a little farther away, in the deep night and the open sea, even if they can fall, will they survive until rescue arrives?
Just as Xu Cang was hesitating, a black ink dot fell on the windshield with a bang.
The dull voice seemed to stir Xu Cang's nerves. He cast his gaze away, and saw more and more ink dots appearing on the windshield. In an instant, these ink dots merged into a stream and flowed down the windshield. .
"It's raining?" Xu Cang frowned, it was clearly rain mixed with volcanic ash dripping onto the fuselage.
If it rains, the impact on the aircraft is not too great, but suddenly, the main warning light of the aircraft suddenly lights up, according to the display, it is a failure of the air source system.
Xu Cang and the captain in charge looked up at the same time, only to see that the light of the No. [-] component was on.
"The components are on?" Xu Cang felt a little irritable. When people are unlucky, misfortunes never come singly.Fortunately, the 747 has three sets of components, and the failure of just one component will not affect too much.
"Shall I do a checklist?" asked the captain in charge.
Xu Cang nodded: "You do it!"
"Okay!" The captain in charge didn't even open the checklist, but started it directly. Of course, this is not a compliant move, but at this time, even the relatively rigid second captain didn't ask any questions, because he I was thinking about the possibility of an forced landing in the Pacific Ocean proposed by the responsible captain just now.
However, it seems that there is no room for thinking now, and they seem to have no other choices.
The responsible captain is quite familiar with the component checklist, and this checklist is often practiced during training.After confirming that the switch for adjusting the air was opened, the captain in charge turned the control selector of the No. [-] component to position A, and then pressed the component reset switch.
Soon, the component's fault information directly became blank, which was considered to have eliminated the fault, and it seemed to be just a small problem.
Xu Cang didn't pay close attention to the action of the responsible captain, but he saw that the malfunction light went out, so he didn't pay attention to it any more.Suddenly, Xu Cang saw a little liquid seeping from the lower right corner of the windshield.
He froze for a moment, stretched out his hand and pointed his finger at the lower right corner of the windshield, and felt a wet feeling at his fingertips.
The captain in charge also noticed Xu Cang's movements, and came closer: "What's the matter? Hmm? Why is there water in the inner layer, is the fog condensed? No! That's seeping in from the outside?"
"Rainwater seeped into the inner layer through the cracks in the outer windshield, but why is the inner glass so poorly sealed?" Xu Cang just finished speaking, and the main warning light came on again. Looking at the prompt, it was still the air source system. Fault.
Perhaps because of the previous experience, Xu Cang first looked at the component lights, and as expected, the No. [-] component light that had just been reset turned on again.
"Turn the control selector to B!" Xu Cang said directly.
The captain in charge nodded, without further ado, he directly turned the control selector of the No. [-] component to B, and then pressed the reset button.
However, the failure information of the No. [-] component did not disappear this time. At the same time, after a short wait, the No. [-] and No. [-] components also turned on the fault lights.
"This!" The captain in charge was taken aback by this, and immediately looked at the pressurization panel, and found that there was no problem with the pressurization of the aircraft for the time being.But if the three components are allowed to fail, it is foreseeable that the aircraft will have problems with pressurization.
"How come all three components are broken?" This was the first time the second captain had seen such a situation.
He has seen one component failure or two component failures. How can all three components fail?This probability is too small.
If the probability of something is so small that it is almost impossible, then it is not a matter of probability, but some other problem that leads to the inevitable occurrence of this failure.
"Could it be the reason for the bleed air?" Xu Cang turned his head and pointed to the wing anti-ice switch: "Turn that off and see!"
"Huh?" The captain in charge didn't understand Xu Cang's motives at first, but he was the captain anyway, so he could quickly remember the reason.
The bleed air of the components depends on the engine. In a high-altitude environment, the air content is already low. At this moment, Xu Cang put all the engines at idle thrust.In this case, the amount of bleed air that the air source system can obtain through the engine is not much.Also, wing anti-icing consumes a lot of bleed air, so there is very little bleed air available to the three components.
In this way, when a very small amount of bleed air is available, the components have to undertake their own pressurization function, which is a bit like letting the components eat grass and milk, and the burden on the components will increase in a short time. Finally overwhelmed and jumped away.
Having figured out this section, the captain in charge immediately turned off the wing anti-ice switches.However, after waiting for a few seconds, all components were reset, and soon all three component lights went out.
"Sure enough, the bleed air is not enough!" The captain in charge breathed a sigh of relief. If there is a problem with the pressurization system, it will take a lot of trouble: "Xu Cang, fortunately, you react quickly!"
Really, the responsible captain is exhausted by now.
Volcanic ash caused too many cascading problems.The presence of volcanic ash likely blocked the pitot tubes, resulting in unreliable airspeed, and the buildup of static electricity from rubbing against the fuselage affected the aircraft's electronic systems, such as the flight management computer.Among them, the unreliable airspeed has the most extended problems. It is precisely because of the existence of unreliable airspeed that it is necessary to open the wing anti-icing switch, and at the same time, the throttle needs to be received by the idle thrust when descending. Insufficient bleed air eventually caused problems with the components.
The crack on the outer layer of the right front windshield was also due to the impact of a larger piece of volcanic rock. As for the sealing problem of the inner windshield, the captain in charge did not know whether it was also related to volcanic ash.
It is precisely because of these problems and failures one after another that all pilots are so afraid of entering the volcanic ash.
However, no matter what, the problem of the component was finally solved.The captain in charge was a little more relaxed just now, and wanted to talk about the possibility of a forced landing at sea.Suddenly, the plane began to vibrate with extremely high frequency and finely, without warning, even the steering wheel that Xu Cang was holding was vibrating left and right.
The discussion of ditching at sea was quickly interrupted by this sudden situation.The vibration of the steering wheel was so violent that Xu Cang couldn't hold on to it.Moreover, the buffeting of the steering wheel is only one aspect, and even the aircraft seems to be vibrating violently.
"Stick shaking?" The captain in charge was stunned: "That's not right! Stall stick shaking isn't like that!"
The first thing a pilot thinks of when the cockpit vibrates is stall shake, which is almost engraved in the pilot's genes.However, every time the cockpit is prepared, the pilot has to test the stall shaker. Pilots are all too aware of what kind of warning the aircraft stick shaker is and what it looks like.
Now the steering wheel is indeed vibrating, but it is still somewhat different from the stall shaker.Moreover, now Xu Cang is setting up the plane according to the chart in the flight performance, and there is no possibility of stalling.
However, compared to the vibration of the steering wheel, Xu Cang suddenly felt that there was something wrong with the plane's descent rate.Because according to the flight chart, under the current attitude and idle thrust, the aircraft's descent rate should be in the early [-] feet per minute, but now it is getting bigger and bigger, almost reaching [-] feet per minute. This gap A little big.
"The descent rate doesn't seem right!" The second captain also discovered this problem.
Xu Cang hesitated, and lightly brought down the rod with his right hand. However, he suddenly felt that the force of the rod was unbelievably light.
"How could this be? Why is the force of the pitch bar so light?" Xu Cang was taken aback, unable to figure out why this happened.
"What did you say?" The captain in charge also took the downstick with his left hand, and he pulled out a long length quite easily, but reflected on the plane, the plane's descent rate increased instead of decreasing. In an instant, it broke through the three thousand feet per minute mark.
Such an abnormal phenomenon directly stunned the responsible captain and the second captain. How could there be a stick to accelerate the plane's descent?This is totally unreasonable!
However, Xu Cang's reaction was so fast, he immediately shouted: "No, it's turbulent flow!"
Then, Xu Cang no longer took the stick, but suddenly pushed the steering wheel forward, and in an instant, the attitude of the aircraft was reduced to minus one degree.
"What are you doing!" The second captain shouted immediately.
Xu Cang's thrusting action directly pushed the plane's descent rate to a rate exceeding [-] feet per minute, and the plane was diving down at an unimaginable speed.
"It's stalled, the plane is stalled!" Xu Cang shouted, "The plane has entered a deep stall!"
"Deep stall, how is it possible?" The responsible captain did not react.But if it's a deep stall, that does explain everything.Under the condition of deep stall, the rudder surface of the aircraft is full of turbulence, and the effect of the rudder surface is almost zero. It is for this reason that when Xu Cang controls the aircraft to pitch, he feels that the stick force is very small.
Because at this moment on the elevator, the airflow has been separated from the rudder surface, the reaction to the stick force is naturally quite small.
The action of the responsible captain and Xu Cang with the stick undoubtedly increased the angle of attack of the plane.The underlying logic of the stall is that the angle of attack of the aircraft is greater than the critical angle of attack, so the procedure for recovering from the aircraft is to reduce the angle of attack.In this way, increasing the angle of attack will increase the stall situation of the aircraft, and the aircraft will naturally accelerate to fall.
However, the problem is that the plane was still fine not long ago, why did it suddenly change from a normal state to a deep stall? This change is too fast?
Suddenly, the responsible captain realized that the only change before that was to turn off the wing anti-ice switches.
"Is it icing?" the captain in charge murmured.
"Freezing rain, it's freezing rain outside, freezing rain that will freeze as soon as it touches the fuselage!" Xu Cang shouted: "The engine anti-icing and wing anti-icing are all turned on!"
"What about the supercharging?" The second captain shouted: "Once the wing anti-icing is turned on, the supercharging will be gone! At this altitude, we can't survive without supercharging!"
At this moment, the outside is full of volcanic ash and cold water vapor.There are no components for pressurization and air circulation, and it is estimated that there will be a large number of casualties among the people in the cabin. How can this be accepted by the second captain.
In his opinion, the angle of attack of the plane is already very small now, and it should be possible to change it.
However, at this moment, Xu Cang suddenly felt that the thrust force of the steering wheel had become extremely weak. With almost no force, he pushed the steering wheel to the end, but the attitude of the plane did not change.
"The effect of the elevator and rudder surface has completely disappeared!?" Xu Cang's face turned pale: "Stall, it can't be changed!"
It's not that I want to procrastinate, but the chain reaction caused by the volcanic ash is much more complicated than the relatively single failure encountered before. The aircraft will fail in various systems. In order to ensure professionalism, we can only use a slightly longer one. Take into account the space.
Of course, I can't be considered a professional, I just try to get closer to the top.
(End of this chapter)
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