It is generally believed that the first stealth aircraft in the world is the American F- 1 17. However, with the emergence of more and more decrypted data, it is found that many companies have carried out related research one after another. The earliest known professional design radar stealth aircraft may be Boeing's "static bird".
Although Boeing disclosed some information about the "Dead Bird" project after the project ended, it is still difficult for the outside world to know all or even some key time points of the project. It is said that this project was carried out in the early 1960s, and some materials were destroyed in the 1970s. The prototype was built at some time in 1962 or 1963.
Unlike the F- 1 17 stealth fighter, the "Quiet Bird" does not adopt a multi-faceted design that is conducive to reducing radar reflection. This is because the big country on the other side of the earth has not put forward the theory of reducing the physical diffraction of radar reflection, so the stealth of "static bird" takes another route. Boeing named "Quiet Bird" 835, and built a semi-scale model for testing. The stealth of aircraft is realized from two aspects: shape design and skin material.
The plane adopts low single wing, V-shaped vertical tail and no horizontal tail. It is said that the aircraft has been tested and its radar stealth ability is good. Why hasn't it been approved by the military? Let's talk about the plane itself. The shape of the plane takes into account the design of reducing radar reflection. The cross section of the aircraft fuselage is generally trapezoidal, the belly is flatter than that of ordinary aircraft, the surface of the aircraft is neat, the engine is buried in the fuselage, and the air inlets are located on both sides of the back of the cockpit.
Moreover, the inlet is arc-shaped, radar waves will not directly irradiate the engine turbofan through the inlet, the tail nozzle has also been removed to reduce the thermal characteristics, and the cockpit hatch cover is coated with metal. The plane does not use the conventional metal skin, but uses a complex non-metallic material.
It may be a "variable density" material, which is literally translated into variable density in English. I don't know what material it is, and I don't know how it works. Boeing played a big game in the "still bird" project. Undoubtedly, the company has realized that stealth fighters will be an important scientific and technological route for aviation development.
The company plans to develop it into a military aircraft with real practical value, including battlefield observation aircraft and stealth attack aircraft. However, the U.S. military believes that the static bird is too advanced, and there is another operational idea in the army that relies on low-altitude terrain penetration. Therefore, the static bird project has not achieved a specific mature model, but Boeing has gained a lot of experience from it, and only obtained "stealth" technology patents, which were kept secret until the 1990 s.
Probably after the "static bird" was terminated, the US military began to focus on the development of stealth aircraft. The difference is that the winner this time is Lockheed F- 1 17. However, the "Quiet Birds" project was not completely in vain. A little shadow can be seen on Boeing's stealth plane, which is a qualitative change brought about by the accumulation of enterprise technology.