In which scenario should the aerial apparatus not be operated over the cab?

Operating the aerial apparatus over the cab is typically not advisable during an uphill attack due to the increased risk associated with the angle of elevation and the dynamics of the situation. When an aerial apparatus is positioned on flat ground and the aerial device is elevated, the risk of the apparatus tipping or experiencing instability is reduced. However, in an uphill scenario, the trajectory changes and can place additional stress on the apparatus' structure.

Moreover, working on an incline can lead to challenges in maintaining stability and control, particularly when water is being directed from the aerial. Such conditions may cause the apparatus to have a different center of gravity, thus increasing the chances of it tipping over if operated over the cab. This is particularly relevant when significant movements or adjustments are made during firefighting operations, which could lead to catastrophe if the aerial device is raised over the cab in such potentially unstable conditions.

In contrast, when handling incidents on flat ground, the apparatus can be more safely maneuvered and operated, as there are generally fewer environmental factors influencing its stability. Similarly, even in high-stress scenarios or with multiple units, provided that the ground is level, aerial operations can be managed with safety protocols in place. Thus, it is in an uphill attack where the risks are substantially higher,