What could happen if the master stream nozzle is not shut down before charging the aerial waterway?

When the master stream nozzle is not shut down before charging the aerial waterway, the high-pressure flow of water can lead to hazardous situations, which includes the potential for serious injury or death. If the nozzle remains open while the aerial device is charged with water, the sudden rush of water can create a dangerous scenario. Firefighters working in proximity to the aerial device could be knocked off their feet, potentially leading to falls or other accidents, especially if they are not prepared for the sudden pressure increase.

Safety protocols in firefighting emphasize the importance of sequential operations - closing the nozzle before charging ensures that firefighters can manage the flow of water safely and avoid unintended consequences. Ensuring that all equipment is properly secured and operated in the correct sequence protects both the firefighters and the civilians in the area from harm.