In a matter of minutes, the plane smoothly enters the runway from the taxiway, then gradually accelerates, looks up, and takes off......

Aside from a slight discomfort during the climb, until he entered level flight, Jojit didn't feel the screeching noise that made his eardrums burst in his memory.

A low roar is unavoidable, of course, but it's more than half the way in terms of the intuitive experience.

"Is the cabin soundproofing well done?"

Naturally, his first thought was to lean over and touch the inner wall of the cabin next to him.

Naturally, it is impossible to find out one or two.

Even if any black technology is used on the aircraft body, it must be placed in the outer hard shell or the middle layer, and the internal bushing, including the inner porthole, will even be divided into the category of "decorative materials" in many cases.

"Mr. Jojit, our flight experience was good, right?"

Gao Quan saw Qiongjit's novel reaction like Grandma Liu entering the Grand View Garden, and knew that the latter was shocked by the noise level in the cabin.

In fact, even he, when he made the first test flight of the 03 full-state prototype of the MA60, he once thought that there was something wrong with his hearing......

The Yun-7 aircraft was originally produced by Hojing, and when he was not transferred to an administrative position, he was responsible for some technical work of this model, and he usually took the old Yun-7 on business trips, so he naturally knew what kind of scene a normal turboprop airliner would be like when it was flying, especially when the take-off and climbing engines were at full output.

However, he was not even standing far from the outside of the wing, and he did not feel the extremely uncomfortable roar.

"Ah...... This...... Not bad indeed. ”

Jojit also realized that his performance just now was really a bit embarrassing, and quickly returned to his original state, but after a few seconds, he couldn't help but be curious in his heart, and asked:

"Did you use any special soundproofing material for the fuselage of the aircraft?"

Finally waited for Gao Quan to this question, of course, he understood what the other party was worried about.

As a representative of the airline, although he was surprised by the quietness of the plane, if he had to choose between cost and cost, he would not hesitate to choose the latter.

All costs are ultimately passed on to travelers.

Those who will fly on regional airlines like theirs are price-sensitive customers, and it is absolutely impossible to accept the increase in fares for the comfort of an hour and a half.

Therefore, his first sentence dispelled Jojit's concerns.

"In terms of fuselage structure and materials, like the vast majority of passenger aircraft around the world, we use ordinary additional honeycomb sandwich structure sound insulation materials, which does not bring additional costs and maintenance difficulties."

The latter breathed a sigh of relief.

Improving comfort is certainly a 100% good thing without increasing costs.

Immediately afterwards, Gao Quancai continued to explain:

"Several other typical turboprop airliners on the market, the peak noise in the cabin during level flight, that is, the noise in our current position is about 80 decibels, and it may reach more than 85 decibels when taking off, this data alone is actually not larger than the passenger aircraft using turbofan engines, but the noise frequency of the turboprop engine is wider, and it is the middle and low frequency part that can easily cause serious discomfort to the human body, and the general sound insulation materials can only filter high-frequency noise, so the passenger experience is very poor."

"And our aircraft uses a biomimetic propeller design, combined with some other control methods, to reduce the noise peak by 2-3 decibels, and focus on reducing the low and midrange, as for the effect, I think you have experienced it, Mr. Jojit."

"Creature what?"

The word biomimicry was too outrageous for a Thai translator who had only been improvised and had to be translated into English, and Rigit was obviously not familiar with such a very noun, but understood the first bio- root.

"Oh, it's the front edge of the propeller that is designed with a comb structure similar to owl feathers, which can significantly reduce the broadband noise of fans below 2kHz, if you are interested, you can take a closer look at our propeller design when you get off the plane."

The design of this comb structure needs to be very subtle, and it also needs to be adapted to the propeller and the engine itself, which is not so easy to learn.

And Rigit is just a professional manager of an airline.

What's more, the leading edge of this comb structure actually has an impact on the efficiency of the propeller, so it cannot be fully optimized for quietness, and if you copy a similar one, the overall performance may be counterproductive.

In fact, what really reduced the noise of this plane was the part that Gao Quan had just said vaguely-

After Chang developed the logic of active wing flutter control, he quickly began to think about how to expand the idea to other areas.

And as we all know, vibration and noise are essentially the same thing.

Since the wing flutter data can be collected and controlled by actively applying vibrations of different phases, it is natural that more regular sound waves can be followed.

That is, the logic of active noise cancellation.

In fact, the 606 Institute has studied similar technology in the past, and they have tried to use active noise control based on speaker arrays on the Y-7, which is the same set found in many luxury cars in later generations, and the effect is outstanding, which can reduce the noise by an astonishing 13-22 decibels.

However, the cost of this set of equipment is beyond the sky, and the weight and power consumption are also quite exaggerated, and it will even directly affect the basic performance of the aircraft, and finally it has to be stopped.

Chang Haonan adopted a different way of thinking.

Although it is also active noise cancellation, he did not install additional audio equipment, but kept a certain phase angle difference between the two propellers of the aircraft to reduce the noise of the propellers on the other side.

In fact, in the initially completed phase angle control algorithm, even the function of automatically calculating the optimal phase angle difference according to the different flight altitudes and speeds of the aircraft has been added, which can achieve optimal noise control under almost all flight conditions.

But the PW127J engine is really lagging behind.

It is still the logic of mechanical hydraulic control at the base, and the control accuracy is even inferior to the AL31FN on the J-10.

Fortunately, the researchers of the 606 Institute later played a lot of new tricks with the electronic controller, although only a fixed synchronous phase angle difference can be used, but compared with other competitors of this era, this advantage is enough.

Rigit's performance just now is the best proof of this.

……

To show the range of the aircraft, the flight experience lasted almost four hours before it ended.

However, after getting off the plane, Rigit did not feel the tinnitus and dizziness that he was almost accustomed to in the past, and at most it could only be regarded as some normal plane fatigue.

After the group returned to the car, Rigit, who had recovered from the shock just now, was no longer reserved:

"Mr. Gao, we need a complete quotation from you, as well as a specific delivery schedule, you know, this is a brand new model of aircraft after all."

The technical source of the MA60 is actually the Y-7, of course, the aircraft itself has been reborn, and the An-24 aircraft has a general reputation in the world, and it is impossible for Hojing to have a pit in his brain to promote the relationship between the two, so the MA60 is a new model in the market.

Compared to sub-model upgrades such as the ATR72-500, the lead time of the new aircraft is undoubtedly a concern.

Especially for an airline like Bangkok Airways, which is itself small, missing out on a peak season is likely to be the difference between life and death.

"No problem, but it takes about two working days to prepare documents in two languages, and in the interim, I thought, let's send someone from the public relations department to take you on a tour of Hojing?"

Gao Quan asked tentatively.

This tour, naturally, is not a real tour.

Doing business, even if it is a very high-level business such as selling airplanes, it is inseparable from the down-to-earth part.

In addition to coming up with excellent products, other aspects of the effort should also be done.

Of course, Rigit is not a White Lotus, it is better to say that this is the part he is waiting for.

"It's okay, then I also take advantage of this time to deeply feel the history of Chinese civilization......"

On the surface, it still has to be high-sounding.

Gao Quan, who was sitting in the row next to him, secretly clenched his fists excitedly.

Although Rigit did not make a clear statement, it is obvious that things have come to this point, and it can be said that they are nine out of ten.

As long as this business can be signed, his name will definitely remain in the history of the development of Huaxia's aviation industry.

Although this is not the first time that Huaxia has exported commercial aircraft – about a decade ago, Ice City Aircraft exported two Y-12 transport aircraft to Sri Lanka.

But the meaning of the two things is clearly different.

On the one hand, the Y-12 is only a small aircraft at the general aviation level after all, and the qualifications required to operate it are completely different from operating a serious passenger aircraft.

On the other hand, the MA60 is the first model to be designed, manufactured and approved by Huaxia using the new CAAC standard.

It can be called a milestone in the aviation industry of Huaxia.

(End of chapter)