How does a pneumatic rain removal system operate?

The functioning of a pneumatic rain removal system is based on the principle of high-velocity air streams that effectively clear rain from the aircraft's windshield. When activated, the system directs a powerful blast of air across the surface of the windshield, creating an airflow that disrupts the raindrops, preventing them from adhering to the glass. This method improves visibility for the pilots by ensuring that rain does not accumulate on the windshield while flying in adverse weather conditions.

The other options do not accurately depict the mechanics of a pneumatic rain removal system. For instance, the use of hot air to evaporate rain may apply to different systems, but it is not the method utilized in pneumatic systems. Similarly, creating a low-pressure zone to suck rain away is more characteristic of suction systems rather than pneumatic systems which rely on air blasts. Lastly, while spraying water-repellent chemicals can help with visibility, this method is not part of how pneumatic rain removal specifically operates.