What is the correct procedure for shutting down an aerial apparatus?

Allowing the engine to idle until it has cooled is a critical procedure for shutting down an aerial apparatus. This practice helps to prevent damage to the engine and other components, particularly after a prolonged use where the machine may have been operating under heavy load. An abrupt shutdown while the engine is still hot can lead to thermal shock, which can create stress on various engine parts and potentially result in engine wear or failure over time. By allowing the engine to cool gradually, you facilitate a gradual decrease in temperature, which is beneficial for maintaining the longevity and reliability of the apparatus.

Checking gauges before shutting down is certainly a good practice; however, it is typically more relevant for ensuring the apparatus is operating correctly during use rather than a critical shutdown procedure. Performing a visual inspection can also be important for assessing the overall state of the equipment, but this occurs as part of routine maintenance rather than as a necessary step in the shutdown process. Turning off the engine immediately does not take into account the thermal and operational considerations that need to be managed for the health of the apparatus.