What must be done to an air chisel before depressing the blade?

To safely operate an air chisel, it is essential to place the chisel against a solid object before depressing the blade. This ensures that the tool is stable and directed towards a surface that can absorb the force generated by the chisel. By doing so, you minimize the risk of the tool slipping or causing an injury, as it allows for proper control and effective use of the chisel's cutting capability.

Using the tool against a solid surface also helps to safeguard against accidents that can occur if the chisel is activated without being properly positioned, which enhances safety for both the operator and others nearby. This practice is crucial in any rescue operation to ensure efficiency and safety.

Other considerations like inspecting the air hose are certainly important for maintenance and ensuring the tool's functionality, but they do not directly relate to the immediate operation procedure needed before using the chisel. Disassembling the tool or recharging it is not relevant to the activation process required for safe and effective use.