No, airplanes cannot become completely invisible in the sense of being undetectable by all means. However, certain technologies and techniques can be used to make airplanes less visible or reduce their radar signature, commonly referred to as stealth technology. Stealth aircraft are designed to minimize radar reflections and be less detectable on radar systems. They achieve this through various means, including shaping the aircraft to deflect radar waves away from the source, using special coatings to absorb or scatter radar signals, and incorporating advanced materials to reduce radar reflections.
While stealth technology can significantly reduce an aircraft's radar signature, it does not render the aircraft completely invisible. Other detection methods, such as visual observation or infrared sensors, can still detect the presence of an aircraft.
Regarding supersonic flight, when an aircraft exceeds the speed of sound, it is said to be flying at supersonic speeds. As an aircraft approaches and exceeds the speed of sound, it encounters a phenomenon called "sonic boom." A sonic boom is the sound associated with the shockwaves created by an object moving through the air faster than the speed of sound.
If an aircraft were to go faster than the speed of sound, several things would occur:
Sonic boom: As mentioned earlier, when an aircraft exceeds the speed of sound, it generates a sonic boom. This sonic boom is a loud noise created by the shockwaves produced by the aircraft. The intensity of the sonic boom depends on various factors, including the size and shape of the aircraft.
Increased drag: As an aircraft approaches and exceeds the speed of sound, it encounters increased air resistance and drag. This can result in higher fuel consumption and decreased efficiency.
Structural considerations: Designing and building aircraft that can sustain supersonic speeds requires careful engineering due to increased stress on the airframe. Special materials and construction techniques are necessary to withstand the forces generated at supersonic velocities.
Regulations: Many countries have regulations and restrictions on supersonic flight over populated areas due to the disruptive effects of sonic booms on the ground. Therefore, supersonic flight is typically limited to designated areas or specific flight corridors.
It's important to note that there are supersonic aircraft, such as military jets and certain commercial planes like the Concorde (which is no longer in service). However, the challenges associated with supersonic flight, including sonic booms and increased fuel consumption, have limited its widespread commercial use.