Which scenario would NOT require an operator to perform a pre-operation inspection on a stacker?

Conducting a pre-operation inspection is crucial for ensuring the safety and efficiency of equipment like stackers. It is a fundamental practice designed to identify any issues before the equipment is used. The scenario that would not necessitate this inspection is when the equipment has just been washed.

When equipment is washed, you generally have a good idea of its cleanliness and condition, assuming no damages or alterations occurred during the cleaning process. However, it is still advisable to visually check for any situations that could have arisen post-cleaning, such as residual water affecting electrical components or any other damage that may have been caused unintentionally.

In comparison, performing a pre-operation inspection before each work shift ensures that the stacker is in safe working order for that day's use. Similarly, checking the machine after a load has been dropped is essential to assess for damages or malfunctions that may have resulted from that incident. Additionally, inspecting the stacker for the first time is critical to ensure that it operates correctly and safely before being used at all.

Therefore, the need for a pre-operation inspection is based on the conditions under which the stacker is used rather than it being freshly washed, making this choice the most suitable scenario where an inspection is not required.