Of course, the C-17 is still far away in the 90s, and McDonnell Douglas' YC-15 was dismounted in the early 80s, so the Y-15plus is the only light tactical transport aircraft with external blowing wing technology that has been mass-produced in today's world.

Its biggest feature is that the blowing flap accounts for 75% of the entire trailing edge of the wing, in other words, except for a small area of the wingtip, most of the other trailing edge of the wing can be deployed downward until the tail nozzle of the engine is completely covered.

So much so that when people look forward at the tail of the aircraft, they will only see the flaps that are deflected and drooped at a large angle like a large bird converging its wing feathers to protect its young.

In this way, the airflow generated by the tail nozzle of the engine will deflect the airflow downwards like a deflector under the action of the drooping wing, and the analysis of the spilled airflow from the middle of the two flaps is also not wasted, because the sagging flaps of the arc just have a "Kangda effect" on the overflow airflow, which guides the airflow to deflect downwards again and continue to generate upward lift.

Coupled with the supercritical airfoil that Tengfei Group has been studying for many years, it can completely transform the strong airflow of the Y-15PLUS engine into full lift when it is started, so as to shorten the take-off distance and complete the purpose of short-distance take-off.

When it lands, the lowered blowing flap can become a good drag reduction mechanism, which cooperates with the drag reducing plate above the wing, the thrust reverser of the engine and the brake system of the landing gear to complete the short landing of the Y-15PLUS.

All in all, a set of blowing wing flap technology gives the Y-15PLUS unrivaled short take-off and landing capabilities.

But with such good technology, why didn't Antonov of the Soviet Union and Boeing of the United States use it, but instead came up with quite alternative An-72 and YC-14?

It's not that I don't want to use it, but this technology seems simple and the principle is not difficult, but it is not easy to create it.

First of all, the idea of using the wake of the jet engine as the lift of the aircraft to take off is really good, but you must know that the temperature of the wake sprayed by the jet engine is not low, and the ordinary aluminum alloy material cannot bear such a high temperature burn, and it will be scrapped by the engine after three or two clicks.

Only high-temperature resistant titanium alloy can do the job, but the problem is that the flap area that occupies more than half of the trailing edge of the wing is so large, and there are so many small connecting rods and other precision parts, if all titanium alloys are used, the cost will definitely soar.

In contrast, the An-72 and YC-14, which use a shoulder-mounted engine layout, only need to wrap a small piece of titanium alloy skin near the tail nozzle to wrap the part of the wing that is burned, and the cost is more than a grade lower than that of similar aircraft with blow-up wings.

Secondly, in terms of handling, the air blowing wing flap is generally divided into two layers, each layer is a movable moving part, which brings a problem, that is, how to make such an important and complex wing moving parts into the operating system of the whole aircraft.

Neither mechanical-hydraulic nor fly-by-wire control is a job that can drive aeronautical engineers crazy, after all, the moving parts of the wing do not have a great impact on the handling of the aircraft, and one can be fatal if one is not done well.

In contrast, the shoulder-mounted layout of the An-72 and YC-14 has no such concerns, except for the strange shape, the air resistance has an impact, the wing is not very complicated, according to the mature aircraft operating system to build, at most according to the aerodynamic factors can be slightly adjusted.

The last and most critical thing is the production and manufacturing, the An-72 and YC-14 aircraft seem strange, but in fact the production and manufacturing process is not more complicated than the traditional transport aircraft, but the position of the engine is different.

It is different for an airplane with a blown wing, and when you look at the wings during a static display, the wings are pressed against the fuselage, but in fact there is extremely cutting-edge aerodynamic technology inside.

In order to realize these technologies and meet the design requirements, the requirements for processing and production are simply high to the extent of changing ~~, not to mention the processing of other supercritical wings, few countries in this world can do it, because the arc and curvature and the final molding can not be described in words.

After listing all this, the pragmatic Soviet Union naturally did not make it so complicated, and the essence of the bear was simple and direct, so there was An-72.

Boeing in the United States has technology, but the capitalists pay attention to saving costs, blowing wings is too expensive, even if it is so expensive to sell it, no one buys it, so there is YC-14.

McDonnell Douglas is the hard resistance of the head iron, the result is that the cost remains high, when bidding for the C-130 follow-up model, the unit price makes the wealthy US Air Force burst into tears, and finally think about it, C-130 is quite good, and it can be used for another thirty or forty years, so McDonnell Douglas YC-15 was cut.

Although McDonnell Douglas used the later C-17 to prove that blowing wings is the mainstream and the king, McDonnell Douglas has been swallowed by Boeing at that time, and C-17 has also become Boeing's top brand from McDonnell Douglas.

Technology that even aviation giants like the USSR and the United States could not afford, can a small Take-off Group afford?

The answer is naturally yes, otherwise Zhuang Jianye's head would have been pumped to engage in such a money-burning thing.

As for why, it is very simple, the United States and the Soviet Union aviation giants engaged in short-distance take-off and landing transport aircraft in the sixties and seventies, when the composite materials had not yet come out of the laboratory, the smelting cost of titanium alloy was expensive and scary, and even the drawings had to be drawn manually, and the penetration rate of high-precision CNC machine tools was not high, which led to the fact that the cost of blowing wings was really not too high.

At the end of the eighties, when the Tengfei Group made up its mind to do Yun-15plus, aviation technology, especially aviation material technology, had a qualitative leap, and aviation processing technology also made rapid progress.

Not only can the production and manufacturing of blowing wings be realized, but the cost is greatly reduced.

Of course, this is not important, the most important thing is that Tengfei Group has accumulated so many years in materials, aviation design, aerodynamic layout, production and processing and other aspects to a certain extent, and can fully control the design, processing and manufacturing of this complex airfoil with blowing wings.

If nothing else, let's take the supercritical wing as an example, as early as the mid-eighties, Teng Airport cooperated with the military to develop a supercritical wing of the non-detectable 8PLUS high-altitude meteorological detection UAV.

After that, a lot of experiments and research were done in this area, and when it came to the development and production of Yun-15plus, Tengfei Group already had rich experience in this aspect, and it was not a problem at all.

As for high-temperature resistant lightweight materials, Tengfei Group has more choices, such as aramid fiber honeycomb structure combined with titanium alloy, carbon fiber reinforced titanium matrix composites, T700 or T800 carbon fiber composites, and even M series carbon fiber materials that are under development to resist higher temperatures and offset greater tensile forces, which are higher than the T-series index.

With CNC shot blasting machine, CNC high-pressure water cutting machine, CNC laser welding equipment, laser additive, flexible fixture, automatic riveting and other modern processing equipment, as well as Tengfei Group's own cost advantages, is it difficult to produce a cost-effective short take-off and landing tactical transport aircraft?