How and why we test the weather radar on the Boeing 737 Weather radar is a vital piece of safety equipment that enables pilots to detect hazardous weather ahead of the aircraft. Weather radar works by transmitting electromagnetic pulses at the speed of light and then measuring how long they take to return from a target. This provides a bearing and distance of weather from the aircraft. The system also measures the reflectivity, which is an indication of the type of weather being detected. Eg wet