The decomposition of the engine, as well as the subsequent cleaning work, do not need Li Tianfeng to worry about, and even the inspection work after the parts are cleaned, which does not need Li Tianfeng to worry about.

However, after all, the engine has completed the life test of 2,000 hours, Li Tianfeng still decided to go to the assembly workshop to have a look, Li Tianfeng grasped it very well, all parts have been cleaned, and when it has entered the strict inspection stage, Li Tianfeng went to the assembly workshop.

After 2,000 hours of life test of the engine, Li Tianfeng knew that the focus should be on those parts, so after Li Tianfeng entered the assembly workshop, he walked straight to these parts.

After such a long time of commissioning, mainly look at the wear and fatigue of some key parts, such as bearings, shafts, sealing honeycomb, sealing grate teeth, turbine blades, etc., as for centrifugal impellers, axial flow impellers, flame cylinders, turbine disc parts, although they are the key parts of the engine, but the service life of these parts is definitely more than 2000 hours, and these parts are generally used until the end of the engine's final life.

Even, until the end of the engine's final life, these parts will not be scrapped, can continue to be used, of course, the engine has undergone three major repairs, the overall life is terminated, even if these parts can continue to be used, they will be scrapped with the engine.

Li Tianfeng's first look is the bearing, these bearings, all are domestic bearings, although representing the highest level of domestic bearings, but limited to technology and materials, compared with imported bearings, there is a certain gap in quality.

In the design of the turboshaft D engine, Li Tianfeng fully considered the performance and quality of these bearings, and adopted some corresponding designs, such as full lubrication, relatively low lubricating oil temperature, etc.

Wearing thin white gauze gloves and holding a small flashlight. Li Tianfeng looked very carefully, and even in order to see more clearly, Li Tianfeng also used a five-fold magnifying glass.

Li Tianfeng looked at it very seriously, Li Tianfeng looked at the main bearings of this engine one by one for a long time, and the bearings had already appeared to a certain degree of wear. But in Li Tianfeng's view, within the acceptable range, there were no pittings.

Experienced people know that the bearings of aero engines are very important, especially the main bearings, which not only reach tens of thousands of revolutions when working, but also bear huge forces and output huge power.

If there are small pitting spots on the bearing balls, this means that the bearing can no longer be used. This is a precursor to fatigue wear, and if you use it again, the pitting of the bearing will become larger, deeper, and will soon be scrapped.

For an aero engine, once there is a bearing problem, it is often fatal, therefore. Li Tianfeng looked at it very carefully and very seriously. I watched it for more than an hour.

After reading the situation of these bearings, Li Tianfeng nodded a little, and estimated in his heart that there should be no problem in continuing to work for another 1,000 hours.

Then, Li Tianfeng looked at the sealed metal honeycomb that was prone to wear and tear, and sealed the grate teeth. These parts basically have a certain amount of wear and tear, but in Li Tianfeng's view, all of them are within the allowable range and can continue to be used.

After reading these. Li Tianfeng also focused on the turbine blades at all levels, the turboshaft D engine first-stage free turbine, the two-stage gas turbine, a total of three-stage turbines, corresponding to the three-stage turbine blades.

Li Tianfeng looked at each turbine blade very carefully, and even carefully looked at the thermal barrier coating on the surface of the blade, the tiny pores of the ultra-cold structure design, and the tenon of the blade.

Due to the relatively advanced design and full consideration in the design, although the blades work in a very harsh environment, high temperature and high pressure environment, and also bear huge centrifugal force, to output huge power, but the overall condition of these blades is relatively good.

Li Tianfeng even felt a little proud in his heart, such a turbine blade, whether it is design or quality, is absolutely top-notch in China, and it is also first-class in the world, and there is no problem in working for thousands of hours.

After spending most of the day in the assembly workshop, focusing on a lot of parts, and after personally looking at these parts, Li Tianfeng knew that it was much better than looking at those inspection reports and boring numbers.

After 2,000 hours of life test, the parts can still reach such a quality condition, and another 1,000 hours of test to reach 3,000 hours of life test, in Li Tianfeng's view, there is no problem.

………

A few days later, the engine is assembled again for another 1,000 hours of life testing, and finally 3,000 hours of commissioning.

After completing the 3,000-hour life test, Li Tianfeng decided to use the engine for a destructive test run.

The so-called destructive test is a test run carried out to determine the maximum service life of the engine, the interval between the first overhaul and subsequent overhauls, as well as to determine the repair method, and to stipulate the service life of various parts and the number of spare parts.

After the engine has been tested for a total of 3,000 hours, it will continue to be tested until the engine is scrapped, so as to verify how long the engine can be used and how long its service life is.

Li Tianfeng estimates that this engine, after 3,000 hours of life test, can continue to work for at least hundreds of hours, or even thousands of hours, and after continuing to work for such a long time, the engine will begin to abnormalize.

If nothing else, Li Tianfeng expected to continue to work, the first abnormality in this engine is the major bearings, after these bearings reach the service life limit, there will be problems one after another, until the entire engine is affected.

Add another 1,000 hours of life testing, the work has already been carried out, and the engine is put on the test bench to start the 1,000 hours of testing.

With the completion of the 2000-hour life test, coupled with the excellent test flight test of the vortex D in various environments in the field, it has won the praise of the military, and the airworthiness certification work is progressing smoothly.

Li Tianfeng has received a formal notice that the airworthiness certification of the first engine will be led by the Airworthiness Bureau, and the expert group composed of various experts will personally carry out the acceptance of Tianfeng Technology Company in the future and issue the airworthiness certificate for the first engine.

The airworthiness certificate of the first engine, generally pay more attention, the airworthiness certification of the follow-up engine, it is impossible to come to the expert group for joint acceptance every time, if the estimate is not wrong, it will be formed by the military and the airworthiness bureau of a joint working group, long-term stationed in Tianfeng Technology Company.

In the future, each turboshaft D engine will be accepted by this team, and an airworthiness certificate will be issued on the spot, of course, the members of this team must be authorized and have this right.

The main users of major domestic aviation enterprises are the military, and the issuance of the airworthiness certificate of each engine is basically the representative of the military stationed in the factory.

A few days later.

The joint acceptance expert team arrived at Tianfeng Technology Company, the team has a total of five people, including Zhang Haiping and Chen Dong are Li Tianfeng's old acquaintances, Chen Dong used to be the military representative of the E factory, this time to participate in the joint acceptance, if nothing else, it will definitely be the military representative of Tianfeng Technology.

The whole process is very smooth, Tianfeng Technology Co., Ltd. got the first engine airworthiness certificate, for this reason, the whole Tianfeng Technology held a celebration, so far, the three certificates of the aero engine are all complete, type certificate, production license, airworthiness certificate.

Soon after, the military representative office in Tianfeng Technology Company was formally established, and the director of the military representative office was Chen Dong. Li Tianfeng was happier in his heart.

Since the user is the military, Tianfeng Technology Company will inevitably have a military representative room, and the main work of the military representatives is the acceptance of the engine and the issuance of airworthiness certificates.

Because of his good personal relationship with Chen Dong, Li Tianfeng was also more polite, and on a certain floor of the office building, Chen Dong was given several offices and a conference room.

………

Beijing, in an office of the military.

A major general wearing an army uniform, was reading a report, this is the performance report of the turboshaft D engine, looked at it very carefully, after looking at it for a long time, the major general said to a major who had been standing next to him: "Xiao Li, this engine is really as good as this report says?" ”

The major said: "Minister, I have already understood, the turboshaft D engine has excellent performance, and it has been tested in the field in the past few months, and the table is also very good, in addition, Tianfeng Technology Company has completed the 2000-hour life test, and Tianfeng Technology has obtained three certificates." ”

"Oh, that's good." The Major General nodded, and then said: "Xiao Li, has the official letter been sent, this time the military autumn order will invite Tianfeng Technology Company to participate, we need a turboshaft D engine." ”

The major said: "The official letter has been issued, Tianfeng Technology will receive it soon, minister, are we really ready to purchase a large number of turboshaft D engines?" ”

The Major General nodded: "Such an excellent turboshaft engine is simply tailor-made for our Wuzhi Shi, we have no reason not to purchase, just ......"

Seeing his minister's groan, the major quickly knew what was going on, and his minister must be worried about the price of the engine.

Seeing this, the major said: "Minister, the price of such an excellent engine is definitely not cheap, should we apply for some more funds from above." ”

The major general nodded: "I'll operate the matter of increasing the application for funds, Xiao Li, assign you a task." ”

"Yes!" Xiao Li immediately stood upright.

Major General said: "Xiao Li, learn more about the quotation of Pratt & Whitney, and in addition, sort out the price of the turboshaft C engine for me, I will be useful." ”

…………

Today's third watch, the third watch will be sent!! (To be continued......)