In modern warfare, one of mastery is the key to winning the battle. But in an aircraft in flight is easy to detect by enemy radar, which has a greater risk. In order to avoid enemy radar monitoring, in airplanes that is coated with a special magnetic materials-absorbing material, which absorbs radar transmitting electromagnetic waves, making little radar electromagnetic wave reflection, so enemy radar can't detect radar echo, unable to find the plane, which would enable the aircraft to reach the purpose of stealth. This is the well-known "stealth fighter". Stealth technology is a hot topic in the field of military scientific research in the world. F117 stealth fighter in the United States is an example of successful use of stealth technology.