What is a critical checklist item during the preoperational check before using a digger derrick?

A critical checklist item during the preoperational check before using a digger derrick is conducting a full range function test. This test is essential because it ensures that all functions of the digger derrick are operating correctly and smoothly before any actual work begins. It allows the operator to confirm that the equipment can extend, rotate, and stabilize as intended, which is vital for safety and effectiveness in the field. If any issues arise during this function test, they can be addressed immediately, preventing potential hazards during operation.

While checking the weather conditions, reviewing load limits and capacities, and inspecting for visual damages are also important components of a thorough preoperational check, it is the full range function test that directly evaluates the operational capabilities of the digger derrick in real-world scenarios. This is why it stands out as particularly critical.