Chapter 161: Let our planes no longer fear frost and snow (two-in-one)
Half a month later.
Nanzheng, at the No. 182 Liulin Airport under the clear sky.
Two propeller planes, one large and one small, are parked at the end of the takeoff runway, waiting for the arrival of weather conditions that meet the test requirements.
They are naturally the Y-8F that has been modified, and the MA-60 prototype that transferred from Haojing a week ago.
On their wings and tails, red, black and yellow ice thickness scales have been drawn——
With the insufficient accuracy of ice detectors, currently only video and high-speed cameras can be used Capture data to obtain data.
Under the leadership of Chang Haonan and Lin Guofan, Factory 182 and the School of Atmospheric Science of Jincheng University have achieved amazing work efficiency.
The former took only more than ten days to move the key area deicing system calculated by Chang Haonan from drawings to reality, while the latter has already established specialized meteorological systems in Jincheng, Qinling and northern Xinjiang. Measurement and control station - Based on the experience of the past few decades, the above places are statistically the places with the highest ice accumulation frequency in the entire China.
However, after everyone waited for a few days, the weather was cloudless and beautiful throughout the northwest.
Under normal circumstances, this is the most suitable climatic condition for flying, but the natural icing test flight is to "face the difficulties" and create difficulties even if there are no difficulties. The current environment seems a bit embarrassing.
"Everyone, check the functions of all the anti-icing systems of the aircraft again!"
Liang Shaoxiu held a big loudspeaker in his hand and shouted to the staff on the other side of the aircraft.
"Mr. Liang, we have checked it three times today, especially the hot air de-icing system. Frequent starting of the engine will also affect the life..."
The deputy next to him whispered with black lines on his forehead. reminded.
Before conducting real natural icing tests, in accordance with the certification standards established by Chang Haonan, Lin Guofan and others, the aircraft first needs to verify the function, safety and performance characteristics of each anti-icing system in dry air.
But because it has been sunny lately, this process has been done too many times.
"It doesn't matter, I guarantee it will be foolproof. Just check it a few times and you won't be wrong."
In fact, Liang Shaoxiu himself knew that doing this would not have any practical effect, but if everyone was kept idle, , which will lead to anxiety or laziness. It is better to find something to do and exercise instead.
"Chang Gong, in fact, based on our previous experience in icing test flights in North America, it is difficult to accurately analyze cloud characteristics in airspace above 1,000 meters by relying on ground weather stations. It is best to have a weather station Detect aircraft and find suitable test airspace in the sky.”
An engineer seconded from Institute 602 said next to Chang Haonan.
The latter rolled his eyes:
"The truth is this, but if you want to modify a weather detection aircraft, you need to pass the natural icing test first, and if you want to pass The natural icing test requires a weather detection aircraft..."
The engineer scratched his head and said nothing more.
"Everything is difficult at the beginning..."
Chang Haonan changed his posture, put his hands in his sleeves, looked up at the sky at an angle of 45° and sighed.
At this time, a piece of English with a strong Italian accent came from the side:
“My friends, you are doing natural knots in this place 1,500 kilometers away from the coastline and without a large water system. Ice test, are you really kidding me?”
The speaker was a tall, thin Italian named Rossi Colombo, a representative sent by AgustaWestland to follow up on the airworthiness certification. Head of the regiment.
It’s not surprising that he thinks so. The natural environment in southern Shaanxi and northwest China is indeed slightly different from the Great Lakes region in North America.
Seeing that someone was questioning his professional ability, Lin Guofan, who had a soft personality, immediately became angry:
“Of course, according to my research over the past ten years, from November to December every year, the Qinling Mountains and northern Xinjiang region The ice accretion frequency value in the airspace is above 50%. Mr. Colombo, you have to learn to be patient, be patient!”
Obviously, everyone was very anxious because they could not conduct the test for many days in a row.
Looking at the two people who had become a little angry, Chang Haonan quickly reconciled the situation:
"Professor Lin, don't worry, everything will be figured out when we find the icing weather, Colombo Mr. is not a stubborn person. Look, he has changed his clothes.”
This sentence was said in English, so Colombo next to him could also understand it——
When he arrived in Nanzheng a few days ago, this guy was wearing a straight velvet suit and insisted This is part of their professional image.
But within two days, he honestly put on a cotton-padded jacket with the aviation industry logo.
Now I can very skillfully imitate Chang Haonan and others by putting their hands together to keep warm.
Colombo looked down at his cotton clothes, pants and shoes, and opened his mouth but did not continue to say anything.
As the bickering between several people came to an end, the atmosphere around the runway became dull and boring again.
At this moment, a rustling sound suddenly came from the walkie-talkie placed on a table next to it, which immediately attracted the attention of almost everyone.
The signal transmission stability of this old analog walkie-talkie is very poor. After it is connected, you have to wait for a while before you can hear clearly what is being said on the other side.
"...Qinling Weather Station reported that it was found that icing clouds that may meet the conditions are forming at an altitude of 1200-1500m. The airspace range consists of the following five coordinate points: 106.108E, 32.473N, 105.906E, 32.459N..."
Lin Guofan grabbed the pen and paper on the table next to him, wrote down the most important data on it, and then quickly gave his judgment:
"The designated airspace range is about 12,000 square kilometers, but judging from the speed of cloud formation, the time window left for us is not very long, and it may only be enough for one test flight."
Natural icing test The best weather conditions are "snowy", so if the clouds are too thick or the temperature is too low and it starts to snow, there will be no conditions for a test flight.
Everyone looked at each other in confusion, and finally turned their attention to Chang Haonan:
"Comrade Xiao Chang, you decide, should the Yun 8 go up first or the Xinzhou 60 go up first?"< br>
“Since the airspace is large enough and the time is short, there is no need to prioritize. I think it is better to let the two aircraft fly together, so that the possibility of successfully collecting data is greater.”< br>
The comrade in charge of Institute 603 and Liang Shaoxiu from Factory 182 looked at each other, and then nodded at the same time:
"Okay, let's test fly together!"
Lin Guofan next to him was at this time He also raised his head:
“I have heard from comrades in the United States before that they will be equipped with random meteorological engineers to make specific decisions based on actual conditions after the plane arrives in the predetermined airspace?”
The engineer from Institute 602 was stunned, then nodded:
"Yes, the flexibility and judgment accuracy of the ground monitoring mode are not enough. It would be much more efficient for meteorological engineers to follow the aircraft."
At this point, he hesitated again:
"But to be honest, the FAA made this configuration based on their in-depth understanding of the meteorological conditions in the Great Lakes region and more than ten years of experience. Our natural icing tests have just begun, and safety is a concern. ..."
Lin Guofan waved his hand and directly interrupted the other party's worries:
"Yu Li, the meteorological conditions in the Great Lakes region have been tracked by the FAA for more than ten years. The meteorological conditions in the Qinling region have been tracked for more than ten years. I have been following the conditions for more than ten years. If the Americans can do the same thing, can I not do it? It is precisely because our natural icing experiments have just started that we need to take some risks to speed up the progress of the experiments. "
"Yu Qing, I have participated in the whole process of the de-icing system design of the Y-8 aircraft. Going to the sky with me can also give more confidence to the crew members participating in the test flight. Comrades Xiao Chang and Xiao Liang are engaged in aircraft design. Zhu Lan They are engaged in surface physics. Instead of letting them increase the risk in vain, it is better to let me go up and be of some use."
"I have made up my mind on this matter, and there is no need to mention it anymore."
At this time, Colombo, who was confused, understood what happened through a translator.
After a brief moment of shock and the embarrassment of being slapped in the face, he quickly rushed over:
“I want to get on the plane too!”
"You?"
Chang Haonan and Liang Shaoxiu both turned their heads and looked at Colombo.
Although as a partner, the latter, representing AgustaWestland, can get permission to take off with the aircraft, the natural icing test is one of the only three Class I risk subjects after all, and one less person will be in trouble. One less risk.
“Don’t worry, I’ve done the natural icing test with the A109 helicopter, I’m experienced!”
Colombo patted his chest and assured:
"Moreover, according to the contract, I must follow all test flight projects in order to get the full bonus given to me by the headquarters."
......
After determining the crew on each aircraft After the members, the two planes that had already completed their pre-flight preparations took off one after another under the command of the tower.
The Qinling area is not far from Nanzheng, so not long after Chang Haonan and others returned to the tower, they received a report that two aircraft had entered the test flight airspace:
"Discovered in the airspace There are large-scale stratus clouds, and the weather conditions above the stratus clouds are fine, which meets the basic conditions for icing test flights.”
The tower commander began to issue instructions one by one according to the requirements of the test flight manual in front of him:
"Check the working condition of the test equipment."
The clear voice of the pilot soon came from the radio:
"Report No. 01, all test equipment is working normally." "Report No. 02, all test equipment is working normally."
"Open the atmospheric parameter detector."
"Checking atmospheric parameters"
"..."
This time the interval between receiving responses is slightly longer:
"The cloud top height is 1800, the atmospheric liquid water content is 0.7g/m, and the average diameter of supercooled droplets is 35 microns, which meets the requirements of the continuous maximum icing test. Request to start vertical cloud detection."
"Requesting approval."
Due to the lack of satellite communication means, after the plane enters the water vapor-rich clouds, the quality of the call between the crew and the tower will drop sharply. Chang Haonan and the others can only hear the stabbing sound. Stinging noise.
Vertical detection of cloud bodies requires the aircraft to enter the cloud from above the cloud body, descend to the cloud bottom and then climb out of the cloud. It records the changes in liquid water content in the cloud during the change of vertical altitude and determines which altitude is most suitable for conducting the test. The whole process will only last about 2 minutes, and the anti-icing system will be turned on throughout the entire process, which theoretically will not affect flight safety.
Nevertheless, not being able to maintain real-time contact with the aircraft is still somewhat nerve-wracking.
Finally, the noise on the radio disappeared.
Lin Guofan's voice reached everyone's ears:
"The cloud base height is 1200, the atmospheric liquid water content is 4.5g/m, and the average diameter of supercooled droplets is 105 microns."
"I It is planned to conduct natural icing test flights at altitudes of 1500 and 1200, each lasting 15 minutes, corresponding to Category 4 and 3 anti-icing capabilities in the airworthiness certification standards.”
Obviously, this is what he wants. Taking advantage of the rare weather conditions in these months, all the test flight items specified in the manual were completed at once.
According to the interim standards formulated by Chang Haonan and Lin Guofan, the anti-icing capabilities of aircraft are divided into 4 categories.
Among them, categories 1 and 2 correspond to imperfect anti-icing capabilities, and flights are only allowed when the weather is fine and there is no risk of ice accretion or a weak risk of ice accretion.
Category 3 corresponds to the ice accumulation conditions in most airspace in the northern temperate zone. Aircraft meeting this requirement can basically fly safely under all normal climate conditions.
The Category 4 anti-icing capability is equivalent to an additional question, and only aircraft expected to be used in environments with more serious ice accumulation risks need to complete it.
The tower commander looked back at Chang Haonan who was standing behind him.
The latter hesitated for a few seconds and then nodded.
"Test flight plan approved!"
......
After receiving the news of plan approval, the two planes turned around and plunged into the thick clouds.
Soon, a dense layer of thin ice formed on the surface of the plane, blocking everyone's view of the outside.
Under normal circumstances, aircraft will deliberately avoid this obviously very dangerous airspace, so whether it is an engineer who randomly takes off or a experienced test pilot, this can be said to be a great opportunity. Quite a special experience.
Especially the navigator cabin on the nose of the Y-8 aircraft, the 270° field of view is completely wrapped in ice. The navigator reported that he felt like he was in an Eskimo igloo.
However, as the ice becomes thicker and thicker, the freshness gradually wears off, and the pilots already feel that the aircraft is becoming more and more difficult to control.
In the cabin at the back, Lin Guofan was staring at the picture on the laptop screen, for fear of mistaking the position of the ice thickness scale.
According to Chang Haonan's previous simulations, in normal configuration and horizontal flight, the ice thickness on the unprotected leading edge of the aircraft wing should reach 7cm to meet the test standards.
"The ice accumulation conditions have met the requirements, and the maneuvering flight test has begun!"
Since it was impossible to communicate with the tower in the clouds, Lin Guofan could only give instructions to the two aircraft together.
“Wait...this is crazy.”
Colombo’s voice came over the radio:
“I just saw on the computer that in the outside atmosphere The water content has exceeded 4g/m! This... This is 4 times higher than the data specified by the FAA!"
"You are right, Mr. Colombo, but we are not the FAA, we are CCAR! .”
Lin Guofan said into the microphone in his hand.
“But...but why is it so extreme? There is no such extreme situation except for blizzards, and it is impossible for planes to take off in blizzards!”
Colombo’s There was some trembling in his voice, as if he regretted following him at this moment.
“Of course it’s for safety, don’t worry, we have the best anti-icing system in the world to ensure your safety.”
“And it’s too late to say anything now, There is no way we can throw you out of the cabin.”
After Lin Guofan finished speaking, he did not talk to Colombo again, but directly ordered:
"Start to hover horizontally and stably."
The pilots of the two planes carefully controlled the rudder surfaces and let the planes start to move towards Perform a stable circling with a 40° slope to the right.
“I...I saw the wing buffet of this aircraft was very large. Is it really...is there no problem?”
Colombo looked pale inside the MA60 cabin. asked the mechanic next to him.
The latter looked up calmly and glanced at the screen of the other camera, then looked back at the laptop in front of him: "It doesn't matter, that's our active vibration control system at work."
"Active vibration control?"
Perhaps because of nervousness, or perhaps because of the cold, Colombo seemed particularly talkative today: ""
"Yes, like... uh, like Like active noise reduction, controllable vibration is used to offset uncontrollable vibration. This is also the core technology of our MA60. Haven’t you seen it in the brochure of our aircraft? "
"Who would read that kind of advertising thing? You are probably the first aircraft manufacturer to make the brochure and flight manual the same thing..."
Colombo's teeth were already chattering.
"It seems that we still have a lot to learn from you in this regard..."
At the same time, Lin Guofan on another plane had already operated a high-speed camera to capture all the All ice growth screens required.
Compared with previous computer simulation results, they are almost completely consistent.
“Hu——”
He breathed a sigh of relief.
To say that I am not nervous about taking off is definitely a lie.
In fact, until just now when he was capturing the ice accumulation, Lin Guofan found that his hands were shaking slightly.
However, the design of the aircraft anti-icing system is based on the simulation of the severity of ice accumulation at different locations. Since the simulation results are correct, it means that the entire de-icing device should also be correct.
“The circling flight and roll subject is over, turn on all de-icing systems!”
...
Since it had been impossible to contact the crew for nearly half an hour, the atmosphere inside the Nanzheng Airport control tower was a little anxious.
Every second feels like an hour
Having confidence in the anti-icing system is one thing, but not being able to hear the pilot’s voice is always unsettling.
Especially Zhu Lan, who was worried about her husband, had been standing in the corner like a sculpture for a long time.
"Unit 01 report."
The sudden clear voice of dialogue made everyone look happy.
“The maneuvering test flight procedures in the landing configuration, standby configuration and approach configuration have been completed. The anti-icing system is working normally and fully meets the test flight qualification criteria. Our two-aircraft formation is ready to return!”
Zhu Lan, who was leaning against the wall, suddenly relaxed and fell directly onto the sofa next to him.
Liang Shaoxiu, who had been tense for more than half a month, was completely relieved and called the deputy next to him:
"Notify the manufacturing workshop to replace the other three Y-8Js with new anti-icing systems as quickly as possible. The finalization schedule of the equipment must not be delayed!"
Chang Haonan, on the other hand, set his sights on The direction of the assembly shop.
There are several other Y-8F platforms waiting for delivery parked there.
He stood in front of the floor-to-ceiling window of the tower and murmured in a voice that only he could hear:
"In this way, it turns out that the tragedies in history should never happen again... ”
(End of this chapter)