When should aerial apparatus not be used for upper-level access?

Aerial apparatus should not be used for upper-level access when a defensive operation is likely because in such scenarios, the primary focus is often on protecting adjacent structures and ensuring the safety of personnel and civilians rather than directing efforts towards upper-level access for rescue or fire suppression. A defensive strategy may require establishing a perimeter and prioritizing water supply and positioning of the aerial in a safe location as opposed to placing the aerial in direct danger or at risk of being compromised by the fire situation.

Using aerial apparatus in a defensive operation can potentially expose the equipment and the crew to hazardous conditions, decreasing overall effectiveness. In these situations, alternative methods such as ground-based firefighting strategies may be more appropriate. The goal is to maintain safety and efficiency without putting personnel in harm's way while they might be better utilized in other operations that don't require aerial access.

In contrast, other conditions like rain, poor visibility, and inexperienced crew members may also create challenges for aerial operations, but they do not inherently classify a situation as defensive, where the primary strategy does not involve the use of aerial apparatus for upper-level access.