When people observe airplanes in the night sky, they notice their glowing lights. Red, green, and white lights are often visible on board. Although from a distance these lights may seem to be installed merely for decoration or illumination, they actually play a critically important role in ensuring flight safety and determining the direction of the aircraft. These lights are usually called navigation or position lights.
Lights of different colors are installed at the ends of both wings of the aircraft. The red light is located on the left side, meaning on the left wing, while the green light shines on the right side. This scheme is established in accordance with international aviation rules so that the direction of any aircraft can be easily understood in the dark. To illustrate this with a simple example: if a pilot sees two airplanes at night and both red and green lights are visible simultaneously, he can assume that the second flight is moving towards him. Furthermore, if only one color is visible, it provides information about the aircraft's position and direction.
In addition to red and green lights, there are also white lights on the aircraft. The white position light mainly helps to show the rear side of the aircraft. Thus, if any flight observes an aircraft from behind, it may see a white light. However, not all white lights are position lights; some of them are strobes, which are flashing anti-collision lights. This is why sometimes a bright flashing white light can be seen on an airplane flying in the night sky, which helps to make the aircraft more visible from a distance.
Many airplanes fly in the sky at the same time. In the dark, it can be difficult to determine the direction of an aircraft just by looking at its shape. Under such conditions, colored lights help other pilots understand the position and course of the aircraft. Suppose two airplanes are flying next to each other. If a pilot sees a pattern of red and green lights on the front aircraft, he can assess its trajectory. This contributes to maintaining a safe distance between both aircraft. Similarly, this facilitates understanding the flight direction for air traffic controllers and ground personnel.
The significance of these lights is most obvious at night, as their light is clearly visible from a distance in the dark. Nevertheless, the aircraft lighting system is designed not only for nighttime. Different lights on the aircraft perform different functions and are used according to flight safety needs. Navigation or position lights serve to indicate the direction and position of the aircraft. Anti-collision lights are intended to increase the visibility of the aircraft. Additionally, landing lights are used to illuminate the runway area and improve the clarity of the aircraft.
Looking at the red and green lights, one might think that on the aircraft they work like traffic lights, where red means stop and green means go. But this is not the case. Here, the red and green colors do not signal the need to stop or move, but rather indicate the left and right sides of the aircraft. Because the red color is on the left and the green is on the right, this helps another pilot understand the direction of the aircraft.
Airplanes fly at altitudes of thousands of feet at high speeds. Under such conditions, having accurate information about the aircraft's position and direction at night is extremely important. Red, green, and white lights simplify this task. The red and green lights of the aircraft indicate its direction, while the white light is related to the rear direction and visibility of the aircraft. With the help of these lights, pilots, air traffic controllers, and ground personnel can better understand the aircraft's position even in the dark. This is why these small lights visible in the night sky are an integral part of the flight safety system.