Chapter 1226

After all, tnb-19b has a length of 42.3 meters, a wingspan of 38.4 meters, a maximum take-off weight of 68.7 tons and a maximum range of 5620 kilometers.

It was originally planned to be equipped with wd-66 high bypass ratio turbofan engine, which is the same as wd-62mvp high-power turbofan engine and the same generation 2.5 17 MW core engine.

The overall structure is inherited from the wd-60 turbofan engine with large bypass ratio before the take-off system, but more mature design and technology are applied, and the basic technical indexes are roughly the same as those of cfm-56 turbofan engine with large bypass ratio which is popular in the United States.

Two wd-66 turbofan engines with large bypass ratio are enough to send tnb-19b aircraft with maximum take-off weight less than 70 tons to fly freely in the blue sky.

After all, the maximum thrust of wd-66 high bypass ratio turbofan engine has reached 10.8 tons, which is almost the same as the latest improved model of cfm-56 high bypass ratio turbofan engine.

Even Airbus A320 and Boeing 737 with take-off weight over 80 tons can be endowed with extremely excellent power performance by cfm-56 high bypass ratio turbofan engine, and wd-66 high bypass ratio turbofan engine can also give tnb-19b the same advantages.

However, up to now, tnb-19b aircraft does not use the powertrain that can be solved by only two wd-66 turbofan engines with large bypass ratio, but uses four wd-56ml turbofan engines with thrust of only 6.5 tons.

This is not because China's take-off is pretentious, but because civil aviation engines have high requirements for safety and stability.

No matter the former Tengfei group or today's China Tengfei group, although it can build a high bypass ratio turbofan engine with the same thrust as cfm-56 high bypass ratio turbofan engine, due to the lack of material, design and system integration, China Tengfei has not been able to make its high bypass ratio turbofan engine as excellent as cfm-56 so far .

After all, for China's take-off, the development of high thrust civil aviation large bypass ratio turbofan is the first time in the world. It is impossible to achieve it overnight. It is necessary to go through the whole process of high thrust civil aviation large bypass ratio turbofan inside and outside before it can be regarded as a formal introduction. Then, it is to use wd-60 and the upgraded wd-66 to polish them slowly.

After all, GM has been able to make Airbus A320 and Boeing 737 fly for decades with two cfm-56. If you want to compete with aviation giants in the future, you can't let your own aircraft run around with two wd-66 platforms, can you?

So from the beginning of wd-60, Tengfei group began to test according to the most stringent standards. The cumulative experiment lasted for 100000 hours, and tens of thousands of modifications were made, so that even wd-60, the mother of the later modified model, was almost unknown.

This is why we have to rename the wd-66.

At the same time, with the establishment of China's take-off, there are more resources in hand, and the tests that could not be done before are no longer difficult problems at this time. Therefore, all kinds of requirements are almost added up, almost to the degree of complete change.

Take the extreme fault of engine fire and explosion for example.

China Tengfei's requirement for wd-66 is that the engine can continue to operate safely under the action of the core aircraft when any point outside the core aircraft explodes and fires, until the aircraft lands safely.

Because of this index, the Department of China's take-off aviation development has repeatedly tested and revised it for several years, only to get a glimpse of it.

Because of this, it will take at least three years for wd-66 to mature.

At that time, Tengfei group was in urgent need of a large-scale platform for testing avionics equipment. European and American civil airliners would be available when they arrived. The problem was that the Navy's anti submarine equipment, the air force's electronic warfare equipment, the integrated avionics system of the next generation of fighters, and the radar on the early warning aircraft. These military type Eastern and western aviation giants were forbidden to apply them to their civil airliner platforms.

There are not so many Russian models of the same kind. The problem is that the Russian products are too rough, and the safety and stability are not yet domestic. It's really a little rough to use.

So at that time, Tengfei group simply set up a new stove and did it by itself.

After all, on the basis of the trj-500, Tengfei group was developing the full-scale design of the enhanced trj-700 regional airliner. Tengfei group took the full-scale design of the trj-700 regional airliner as the blueprint. The width of the cabin was inconvenient and the fuselage and wingspan were further extended.

At the same time, move the engine tail POD under the wing.

However, the lengthening of the fuselage and wingspan made the total structure of the aircraft increase in a straight line. The thrust of the wd-56ml turbofan engine originally used in the trj-700 regional airliner was obviously insufficient, but the wd-66 was not as mature as it is now. What should we do?

At that time, Lin Guanghua, who was in charge of the project, learned from laomaozi's practice. If the thrust was not enough, he added two more engines and turned them into four engines. Wouldn't the thrust go up?It's simple and crude, but it's very effective.

As for the cost of fuel consumption and maintenance of the four engines is too high, and there are some defects that are not worth the loss. Both the then Tengfei group and today's China Tengfei really don't care. After all, tnb-19b is just a test and verification machine. In addition to the stability and safety, the most important thing is that the cost of each modification of tnb-19b is not low, and all kinds of internal equipment are dismantled It's no big deal to maintain two more engines in the process of assembling and disassembling.

However, although the four wd-56ml turbofan engines can set off the tnb-19b, the thrust of the wd-56ml turbofan engine is too small. In addition, the 42 meter long fuselage of the tnb-19b aircraft still uses the 3.5 meter wide diameter of the trj-700 regional airliner. As a result, the whole fuselage is particularly slender, which makes the small wd-56ml turbofan engine even thinner.

So many people in the aviation industry will make fun of tnb-19b: "it won't be driven by five Apus, will it?"

Of course, compared with the five Apus, tnb-19b aircraft is more called sausage.

It's really long and thin, like a sausage.

However, whether it's the banter of five Apus or the joke of sausage, when there is no plane that can hold hands at home to pick up the Chinese in the Balkans.

This atypical aircraft with the nature of emergency is the most suitable model, because the tnb-19b aircraft is basically an expansion of civil aircraft, which applies a lot of trj-700 regional airliner technology, and even in the fuselage parts, the two models can be used to a certain extent.

Besides, the most important thing is the voyage. Although it is impossible to fly directly from the eastern part of China to the Balkans for 5620 km, it is more than enough to start from the border areas.

Even if for various reasons, we can't fly to Belgrade through Turkey and need to go around Russia's Black Sea area. After passing through Romania, we have to make a big detour to enter the country, but tnb-19b can still easily overcome it.

Based on these rigid indicators, after reviewing the report submitted by Zhuang Jianye, the higher authorities immediately agreed to the request and began to carry out emergency modification on the tnb-19b aircraft before flying to Belgrade.

As for the effect

The leader of the foreign affairs department, who had just landed, summed up his words: "at that time, we saw that we were airplanes made in our own country, and those foreign countries who wanted to watch the excitement were all green!"