"You're saying there's something wrong with the EDM process?"

Zhong Shihong next to him showed an expression of disbelief:

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

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

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

"I think it's more likely that there were gaps in the post-processing and inspection process."

"This ......"

Zhong Shihong still can't accept this explanation:

"Turbine blades are the core components of the hot end of aero engines, so we have set up a special inspection process to check the position, hole diameter, residual stress and deformation of the hole, as well as the burr and flash of the orifice, and only when they pass can they be installed on the turbine disk."

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

Looking at Zhong Shihong, who was explaining the quality inspection process at a rapid pace, Chang Haonan hesitated for a moment, and did not directly say what he had just thought.

"I need a metallurgical microscope with a probe."

There's no point in arguing here, it's the right thing to do is to find a sample to come over and test it.

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

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

"Multi-functional probes cannot be produced by themselves in China for the time being, and if they are imported, we can't buy high-end optoelectronic instruments and equipment in our military units."

Hearing this answer, Chang Haonan shook his head helplessly.

In this era, the backwardness of Huaxia's technological level is all-round, and many things are powerless, and it is difficult for him alone to solve this kind of systemic problem in a short period of time, so he can only think of other ways.

"What about other units, do you know which university or scientific research institution has this kind of equipment?"

In the era before Chang Haonan's rebirth, a place for scientific research required several similar electron microscopes, so he rarely paid attention to this kind of problem.

"Perhaps...... Can you ask Lianhai University of Technology, or Lianhai Medical University? ”

"I'll get in touch."

The inspection engineer quickly turned away.

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

The ultimate goal is the same, which is to solve the technical problems that caused the failure of the turbojet 14B.

Whoever is right will know everything when the test results come out.

……

The two universities to communicate with are not universities under the Commission of Science and Technology, and the turbine blades of the turbojet 14 still have secret problems after all, so the communication between the cross-system took some effort, and it was not until dinner that day that the 410 factory received a clear reply.

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

In the 90s, there were not many people who took planes, even if it was for business or business trips, most people would choose planes when they went far away, so even though Shengjing and Lianhai were not small cities, there were still not flights every day.

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

A Cessna 208, nicknamed the "Caravan".

Even regional planes are not considered small aircraft, in fact, they are generally used in the field of general aviation abroad.

In fact, Chang Haonan didn't even know this plane at first, but he simply felt a little familiar.

It wasn't until after he boarded the plane that he looked at the escape manual behind the front seat before he took off, and then determined the specific model.

also remembered the familiar source -

When he was just reborn more than half a year ago, in Liu Hongbo's flight design class, Huang Zhiqiang's group came up with a seaplane design based on this aircraft.

It's just that he's now riding in an extended version, which can accommodate 14 passengers.

"I didn't know that Northern Airlines still had so many small Cessna planes."

During the take-off and climb of the plane, Chang Haonan looked down from the porthole and found that there were many similar models parked on the apron next to him, and the paint was also the same.

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

Zhong Shihong, who was sitting next to him, wrapped the blanket he had asked for from the flight attendant before getting on the plane, and replied:

"There are also slightly larger regional models that are also very popular, such as the MA60 that you have participated in before, Bombardier's CRJ200, and Embraer's EMB145 that has just been put into operation, and there are quite a few of them."

Chang Haonan, who heard this, was shocked:

"Wouldn't it cost you to operate so many small planes?"

I can't do any serious work on the plane this year, so the two of them can only chat and pass the time like this.

"How so?" Zhong Shihong also asked a little confusedly:

"At present, the mainstream prediction of air passenger transportation in the new century is to concentrate passengers in regional central cities through small short-haul passenger aircraft, and then connect these central cities by super-large passenger aircraft, and the expected demand for regional aircraft and general aviation will be very large."

"So in the past two years, Embraer and Bombardier have been developing a new generation of regional airliners, ERJ190 and CRJ700, and like Boeing and Airbus, the focus of research and development is on those ultra-long-range trunk airliners."

After such a reminder from the other party, Chang Haonan finally remembered that it seemed that in the 90s, there was such a trend, and he felt that the future development direction of passenger aircraft would be very large or small, which made several major technology manufacturers take a lot of detours.

It was not until the new century really dawned that everyone realized that the reality was completely different from what they imagined.

No one wants to go through so many transfers and try to choose direct flights, and air passenger traffic is growing much faster than expected, especially in places like China and North America, where even routes between two non-major cities are worth flying by small mainline airliners.

Therefore, ultra-long-range or super-large behemoths such as Boeing 777 and Airbus A380 quickly fell out of favor, and before Chang Haonan crossed, there were few passenger flights operated by these models.

As for the regional airliner that was once pinned on high hopes......

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

Of course, if you only look at the results, the 150-180 seat class models such as the Boeing 737/Airbus A320 have always been the absolute rulers of the market, but in the short period of time at the turn of the century, their position in the minds of airlines and aircraft manufacturers did have some twists and turns.

And this seems to be an opportunity that can be exploited.

(End of chapter)