chapter  20
Weather radar
Pages 1

Weather radar (WXR) was introduced onto

passenger aircraft during the 1950s for pilots to

identify weather conditions and subsequently

reroute around these conditions for the safety and

comfort of passengers. Extreme weather

conditions are a major threat to the safe operation

of an aircraft. Approximately 33% of accidents

are weather related; flight crews need to be

aware of these conditions and understand the

consequences. In the age of digital data com-

munications, aircraft systems, e.g. aircraft

communication addressing and reporting system

(ACARS), can receive and transmit information

about prevailing weather conditions. The onboard

weather radar, however, provides the crew with

their main source of identifying extreme weather

conditions. A secondary use of weather radar is a

terrain-mapping mode that allows the pilot to

identify features of the ground, e.g. rivers,

coastlines and mountains. Various features are

being added to weather radar systems to provide

many benefits including enhanced displays and

improved turbulence detection. In this chapter we

will review some basic radar principles, and

examine the principles of weather radar including

the detection of severe turbulence and lightning.