Z-20 Low Observable Helicopter

In May 2021, a media report revealed a scale model of what seems to be a stealth helicopter on display at a facility of the China Helicopter Research and Development Institute. Some said it could be a stealth variant of the Z-20. Stealth helicopters have a huge strategic and tactical role in modern warfare. Due to the special value of stealth helicopters, China's research and development of the improved stealth Z-20 has been put on the agenda. With the advent of the J-20 and J-31 fifth-generation fighters, the technical problems of stealth have been solved, and there are not many technical barriers to the development of the stealth version of the Z-20.

According to a report by the state-run Global Times on 01 June 2021, Chinese military expert Fu Qianshao said on the above statement, “From the public images, foreign media judged that this is a model of a stealth helicopter, and I personally think this judgment is no problem.” But he believes that it is impossible for Western media to speculate that China is copying the invisible "Black Hawk" of the United States.

From the appearance point of view, this stealth version of the Z-20 adopts an angular aerodynamic shape design that is conducive to reducing the radar wave reflection area, and is painted with a similar color to the stealth coating of the J-20 stealth fighter. Infrared signal processing is also done to suppress. Compared with the ordinary version of the straight 20, the entire stealth version of the straight 20 has a big change in appearance, and it looks very sci-fi advanced.

The stealth version of the Black Hawk is a highly modified Black Hawk helicopter. The entire tail is covered with a substance similar to radar-absorbing paint, and it is also equipped with a stealth-designed tail cone. The tail rotor in the shape-preserving disc is one more than that of the Black Hawk, reaching 5 blades. The sound of this specially designed tail rotor is no longer the sound of ordinary helicopters, but a more muffled sound.

There are major improvements of the Stealth Z-20 worth mentioning. The overall design is better than the U.S. military's stealth Black Hawk helicopter. The Chinese modification of the Z-20 helicopter in question has a trapezoidal airframe, and the exhaust appears to be directed into an enlarged tail boom and out of the upper ventilation system to minimize the infrared signature. The tail of the helicopter looks less convoluted than that of the American Stealth Hawk.

On May 1, 2011, the terrorist tycoon bin Laden was killed by the US military. During the operation, the US military lost a helicopter, leaving behind a mysterious tail rotor wreckage. The world knows that the US military special forces have been equipped with top-secret stealth helicopters. Aviation experts believe that the helicopter that crashed in Pakistan was a modified "Black Hawk" helicopter, and the related technology is highly classified. Judging from the tail rotor of the fallen "Silent Black Hawk" stealth helicopter, the aircraft has extensively applied the research results of the RAH-66 "Comanche" light stealth armed helicopter. The tail can effectively reduce the air friction noise.

When traditional helicopters fly at high altitudes, their large radar cross section will inevitably make the ground "detected", while low-altitude flights are bound to generate more noise, both of which are bound to have a significant impact on special operations such as surprise attacks. It is conceivable that the "Silent Black Hawk" was born to solve these two deficiencies.

Since China has successively launched a number of stealth fighter jets/UAVs, no one will question China's achievements in key technologies such as stealth skin, stealth paint, and stealth modeling. Therefore, there should be no technical difficulties in designing and manufacturing a helicopter with the same low electromagnetic wave characteristics as "Comanche" and "Silent Black Hawk".

The "War Zone" column of the US "Power" website published an article on 30 May 2021, saying that the helicopter model exhibited in China seems to be a stealth version of the Z-20 medium-sized helicopter, and the design of China's "stealth version of the Z-20" may be copied from the United States. Over the decades, "China has stolen vast amounts of U.S. aerospace secrets from nearly every major U.S. manufacturer and defense agency," the article said. In addition, one piece of evidence is that the tail of the crashed stealth "Black Hawk" once fell into Pakistani hands.

When the dropped stealth "Black Hawk" was blown up at Osama bin Laden's compound, its tail was still intact. Pakistan then shipped the remnant tail and used it as a geopolitical bargaining chip. After about 3 weeks of intense diplomatic struggles, the tail of the helicopter finally returned to the United States. The United States still forced Pakistan to return the wreckage of the helicopter. But those days that the tail was at the disposal of the Pakistani military might well have been enough to familiarize the Chinese engineers with it. The "stealth Black Hawk"'s exotic tail design includes its covered propeller hub, multi-blade design, and composite structure, which are also reflected in China's stealth helicopter models.

In this regard, Chinese experts said that this is a common tactic used by Western media, and the "copying theory" is completely false. Because the United States itself is very strict with the secrecy of this stealth helicopter, no clearer photos have been released so far. The outside world has only seen one of its tails, and this tail was left when bin Laden was killed. At that time, due to the influence of low-altitude weather conditions and pilot control problems, the helicopter crashed, and the US military blew it up, but the tail oar did not have time to blow up, so a few blurred photos were taken for the media.

Fu Qianshao, a well-known military expert in China, commented on this statement, and asked the US media, "Can it be plagiarized with a few photos?". "Based on this photo alone, can we imitate it? Even if there is a clear photo, who can imitate it at a glance? What's more, compared with the previously circulated American stealth version of the "Black Hawk" helicopter, There are still some differences in the design of this model in China. So the so-called plagiarism is unfounded.”

Making military weapons is not something that can be done in a similar fashion. It involves all aspects of various subsystems and weapon design. It is impossible to imitate such an advanced and cutting-edge stealth helicopter with just a few photos. In fact, as Fu Qianshao said, there are quite a few "weapon plagiarism theory" that the United States has raised against China in recent years.

This time, China's "stealth version of the Zhi-20" model has caused heated discussions after its debut. Compared with before, the improvement of China's "stealth version of Zhi-20" is very obvious. First of all, its shape change is the design of the tail nozzle. It does not use the traditional engine row. Instead of the air pipe, two rows of exhaust holes are used on the tail beam. The high-temperature exhaust gas generated by the engine can enter the exhaust holes through the pipe, and finally mix with the external cold air before being discharged from the body.

As for the performance of the "stealth version of the Z-20", its fuselage head is more similar to the J-20. It belongs to the stealth nose design. The body is diamond-shaped. is downward sloping. This shape design can reduce the vertical exposure of the helicopter, and can also refract enemy radar waves, and the tail nozzle also adopts a stealth design, and the engine compartment and intake/exhaust ports can be wrapped, which can reduce the detection probability.

When asked if a stealth helicopter is in development, Deng Jinghui, the chief designer at the China Helicopter Research and Development Institute of the state-owned Aviation Industry Corporation of China, did not give a direct answer, but said 12 January 2022, "Helicopters are low-altitude killers that play a unique role in special operations. I'm also interested in this question, so let's look forward to an answer together." The stealth helicopter could be a forward research project, and this type of aircraft could be a good choice in assault and penetration missions, since it is more difficult to spot and has a higher chance of survival, Fu Qianshao, the Chinese military aviation expert, told the Global Times.