The military-industrial scientific research system of the academic master.

"You mean, there's something wrong with the EDM process?"

Zhong Shihong next to him showed an expression of disbelief:

"But the turbine blades of the Turbojet 14 were produced in the same way in the past, and there were no similar failures?"

"It's not necessarily a problem with the processing technology itself."

Chang Haonan habitually raised the turbine blade in his hand and pointed it at the light source, but it was obviously impossible to see anything with the naked eye, not to mention that this was a scrapped part:

"I think it's more likely that there was an oversight in the post-processing and testing process."

"This……"

Zhong Shihong still can’t accept this explanation:

"Turbine blades are the core components of the hot end of aeroengines. For this purpose, we have specially set up a set of inspection procedures to inspect the position, diameter, residual stress and deformation of the openings, as well as the burrs and flash edges of the openings. Only if they all pass before it can be installed on the turbine disk.”

"So, although the yield rate of manufacturing turbine blades is not high, I think the quality of the product can be guaranteed."

Looking at Zhong Shihong beside him who was explaining the quality inspection process quickly, Chang Haonan hesitated and did not directly express what he had just thought.

"I need a metallographic microscope with a probe."

There is no point in arguing here. The correct way is to find a sample and test it again.

"We do have a metallographic microscope here, but this scanning probe..."

An engineer in charge of testing next to him shook his head:

"Multifunctional probes cannot be produced domestically for the time being. If they are imported, high-end optoelectronic instruments and equipment cannot be purchased by our military industrial units."

Hearing this answer, Chang Haonan shook his head helplessly.

China's technological backwardness in this era is all-round, and many things are out of control. It is difficult for him alone to solve such systemic problems in a short period of time, so he can only think of other ways.

"What about other units? Do you know which universities or scientific research institutions have this type of equipment?"

In the era before Chang Haonan was reborn, a place doing scientific research would only need a few similar electron microscopes, so he rarely paid attention to this kind of issue.

"Perhaps... you can ask Lianhai University of Technology or Lianhai Medical University?"

"I'll get in touch."

The testing engineer just turned around quickly and left.

Although Zhong Shihong had different views from Chang Haonan, he did not stop him.

Everyone's ultimate goal is the same, which is to solve the technical risks that cause the turbojet 14B to malfunction.

No matter whose opinion is correct, everything will be known once the test results come out.

……

The two universities that needed to communicate were not affiliated with the Commission of Science and Industry, and after all, there were still confidentiality issues with the turbine blades of the Turbojet 14, so the communication between the systems took a lot of effort. Until dinner that day, the 410 Factory Biancai received a clear answer.

Lianhai Polytechnic has a metallographic inspection microscope that meets the requirements, but according to the agreement reached with a foreign company at the time of purchase, this equipment and all related accessories cannot be moved, so the samples need to be brought there for testing.

In the 90s, there were not many people flying. Even for official or business trips, most people only chose to fly when traveling far away. Therefore, even though Shengjing and Lianhai are both large-scale cities, they still do not fly every day. flight.

Therefore, it was not until a few days later that Chang Haonan and Zhong Shihong boarded a plane to Lianhai with several engineers and two finished turbine blades randomly selected from the production line.

A Cessna 208, nicknamed "Caravan."

Small aircraft that are not even considered regional aircraft are actually generally used in general aviation abroad.

In fact, Chang Haonan didn't even recognize the plane at first, but simply thought it looked familiar.

It wasn't until after he boarded the plane that he glanced at the escape manual placed behind the front seat before taking off that he determined the specific model.

I also remembered the familiar source——

When I was reborn more than half a year ago, in Liu Hongbo's aircraft design class, the seaplane design presented by Huang Zhiqiang's group was based on this aircraft.

It's just that the one he's riding now is an extended version that can accommodate 14 passengers.

"I didn't know before that Northern Airlines actually had so many small Cessna aircraft."

As the plane took off and climbed, Chang Haonan looked down from the port window and discovered that there were many of the same models parked on the apron next to them, all with the same painting.

"A lot of airlines have been doing this over the years."

Zhong Shihong, who was sitting next to him, wrapped himself in the blanket he asked from the flight attendant before boarding the plane and replied:

"There are also slightly larger feeder models that are also very popular, such as the MA-60 that you have participated in before, Bombardier's CRJ200, and Embraer's EMB145 that has just been put into operation. There are a lot of them."

Chang Haonan was shocked when he heard this statement:

“Aren’t we going to lose money if we operate so many small planes?”

It's impossible to do any serious work on the plane these days, so the two of them can only pass the time by chatting.

"How could it be?" Zhong Shihong also asked in confusion:

"The current mainstream forecast for air passenger transport in the new century is to use small short-distance passenger aircraft to gather passengers to regional central cities, and then use super-large passenger aircraft to connect these central cities. The demand for regional aircraft and general aviation is expected to be very large."

"So in the past two years, Embraer and Bombardier have been developing a new generation of regional airliners, the ERJ190 and CRJ700. For example, Boeing and Airbus are focusing on ultra-long-range mainline airliners."

After being reminded by the other party, Chang Haonan finally remembered that in the 90s, there was a trend that the future development direction of passenger aircraft would be very big or very small, which made several major technology manufacturers And took many detours.

It was not until the new century came that everyone discovered that the reality was completely different from their imagination.

No one wants to go through so many transfers and will try their best to choose direct flights. Moreover, the growth rate of air passenger traffic is much faster than expected, especially in places like China and North America. Even the route between two non-major cities, It is also worth flying with a small mainline airliner.

Therefore, ultra-long-range or ultra-large giants such as the Boeing 777 and Airbus A380 quickly fell out of favor. Before Chang Haonan traveled through, there were very few passenger flights operated by these models.

As for the regional airliners that once had high hopes...

It is not difficult to see some clues from the fact that Bombardier and Embraer have sold themselves to Airbus and Boeing respectively.

Of course, if we only look at the results, 737-320-seat models such as the Boeing 150/Airbus A180 have always been the absolute rulers of the market. However, in a short period of time at the turn of the century, they were The status in the minds of companies and aircraft manufacturers has indeed had some twists and turns.

And this seemed like an opportunity that could be exploited.