Turbulent weather can lead to passenger discomfort and, in extreme situations, can jeopardize the safety of the flight. To avoid flying into turbulence, the navigation systems must constantly provide information about the weather conditions ahead of the aircraft. To achieve this, the aircraft is equipped with a weather radar system.

The system has a high directional flat plate antenna in the radome of the aircraft and two weather radar computers in the avionics compartment. The computers are connected to the antenna with the help of waveguides. The weather computer controls the antenna using motors to perform an auto scan. The antenna can scan 80 degrees vertically and 180 degrees horizontally.

The weather radar system works on the echo principle. The selected weather computer generates high-frequency radio pulses in the range of 4 to 6 gigahertz and transfers them to the antenna through the waveguide. The antenna converts it into a narrow beam and transmits them ahead of the aircraft. The aircraft radome is made of special composite material which causes minimum interference to radio wave propagation.

Let's see how the system detects, calculates, and displays all possible weather conditions the aircraft can encounter. The radio pulses transmitted get scattered by the precipitation in the clouds. Some of them are scattered back towards the antenna. The weather computer tracks the direction of the returning pulses by using the antenna position data. Then it calculates the range by using a simple formula: c is the speed of radio wave propagation, which is the same as the speed of light, t is the elapsed time between transmission and reception, and dividing by two since the pulses have traveled twice the distance.

Finally, the computer measures the intensity of the radio pulse return. The higher the precipitation in the clouds, the more will be the echo of radio pulses. This means radio pulses hitting dense stormy clouds will have more returns compared to light weather clouds. The weather computer, now knowing the direction of the return, the distance from the clouds, and the intensity, maps out the weather condition ahead of the aircraft on the navigation displays.

Different colors signify different weather conditions, which are directly proportional to the intensity of the return. Green indicates light weather, yellow for medium, red signifies heavy conditions, and magenta for turbulence. The weather system provides information on turbulent weather conditions up to 40 nautical miles. With the help of the weather radar system, aircraft can be navigated to avoid turbulence, ensuring comfortable and safe flights.