A load applied at an angle to the vertical plane of the boom describes:

When a load is applied at an angle to the vertical plane of the boom, it creates a condition known as side loading. This situation occurs when the line of action of the load does not align directly with the boom's structure, resulting in lateral forces acting on the crane's components. Side loading can potentially lead to structural damage or instability if the crane is not equipped to handle these forces.

Understanding side loading is crucial for crane operators, as it can affect the crane's balance and load capacity. Recognizing this concept enables operators to take the necessary precautions to mitigate potential hazards, ensuring safe and effective operation during lifts.