In recent years, many fighter jets with duckwing layout have actually emerged, such as some fighter jets from Russia, Sweden, France, Israel, and China, including Europe's JAS-39 "Eagle Lion", "Rafale", "Typhoon" fighter jets,Russia's Su-30SM, and China's J-10 fighter jet, especially China's J-20, which is currently the only fifth generation stealth fighter jet that uses duckwing layout.

The so-called "duckwing layout" refers to a aerodynamic design layout of a fighter jet with a pair of small wings in front of the main wing,with the duckwing at the front and the main wing at the back, while the traditional fighter jet design layout has the main wing at the front and the flat tail at the back. The US military hates duckwings very much. So far, all US fighter jets have a conventional layout, and there is not a single active duckwing layout fighter jet. Only the F-14A Tomcat carrier based fighter jet has a pair of retractable but non deflectable small wings in the wing sleeve. So the question is, why doesn't the US military like to install duckwings on fighter jets? Why hasn't the United States officially installed a duckwing layout fighter jet yet?

Firstly, the duckwing aerodynamic layout is an aircraft design with distinct advantages and disadvantages. After adopting a duckwing layout, the main wing lift of the fighter jet can be increased, resulting in a higher lift to drag ratio and improved lift coefficient, thereby enhancing the aircraft's flight performance. It can also shorten the takeoff distance of fighter jets and increase their maximum takeoff weight.

Taking the J-10 fighter jet as an example, although the thrust to weight ratio of the J-10 fighter jet is not high due to engine performance limitations, its high angle takeoff distance is only 250-300 meters, and the duckwing layout design is obviously indispensable.

Duck wings can generate very special vortices, which affect the stability of fighter jets. There are extremely complex interfering airflows between the wing surfaces, so a large number of wind tunnel experiments and engineering calculations are necessary to obtain a relatively excellent fuselage wing surface design. Even with excellent design that ensures perfect data between the wings, duck layout aircraft still have drawbacks such as complex flight control systems and poor landing performance.

Americans always believe that the canard layout is a kind of "opportunistic" aircraft design. It is a "shortcut" in engineering that has to be adopted when the engine performance is insufficient. Naturally, there will be a situation of "gain and loss".

Due to the world-class level of the United States in the field of aviation engines. Having multiple military aviation engines with advanced performance and powerful thrust, it is possible to achieve all design performance requirements using a very conventional layout, so there is no need to waste a lot of effort choosing more complex duckwing layout designs.

For example, for high thrust military turbofan engines, a single thrust of 20 tons is considered the top level, and only the F135 turbofan engine from the United States can achieve this indicator. The F135 engine is currently the world's largest military small bypass ratio turbofan engine in terms of thrust. Many countries have also launched attempts to catch up with its huge thrust data, but so far it has not been successful.

For aircraft designers in Russia, Europe, and China, because the aircraft engines are slightly inferior to those in the United States, but they do not want to lower the design performance indicators of new fighter jets and want to have stronger flight performance, they must do everything possible to improve the lift to drag ratio of fighter jets, and the duckwing layout is the optimal solution.

It is believed that the excellent aerodynamic design of the J-20 stealth fighter developed by our country is actually to compensate for the lack of engine thrust. The backwardness of Chinese aviation engines has also greatly limited the development of Chinese fighter jets.

But our designers, relying on advanced aerodynamic design, still enabled the J-20 to achieve good flight performance. The unique aerodynamic design of the J-20, consisting of "duck wings,wing strips, front and rear flaps, and fully moving tail fins, " makes it more flexible,maneuverable, and faster in aerial combat. Moreover, the full dynamic canard wing of the J-20 did not affect its stealth performance.Americans have always hated and despised fighter planes with canards. The US Air Force has a famous saying: "The canards are best installed on the enemy's aircraft! "But things changed in September last year, when US Air Force Assistant Secretary Will Roper stated that the next-generation NGAD technology demonstrator had already undergone flight tests. This is the technology lead aircraft for the US sixth generation fighter jet; The experimental aircraft has completed its actual maiden flight and set many new records during the test flight& quot;

Although the United States has not released detailed information on the sixth generation fighter jet, it has been revealed that the aircraft will adopt a wing design without a vertical tail and a duckwing layout similar to the J-20 fighter jet. Previously, American military experts had great contempt for the J-20, believing that the duckwing had no stealth performance. However, the sixth generation aircraft of the United States surprisingly had a duckwing design, which is not admitted on the surface, but is honest with the body.

Source: Military of Strong Countries