What safety measure should be taken during APU operations in confined spaces?

Ensuring adequate ventilation during APU operations in confined spaces is crucial for safety. The Auxiliary Power Unit (APU) generates exhaust gases and heat, which can accumulate in poorly ventilated areas, creating a risk of asphyxiation or fire. Proper ventilation allows for the dissipation of harmful exhaust fumes, reduces the concentration of combustible gases, and helps maintain a safe temperature, thereby protecting personnel from potential hazards.

While other safety measures, such as fire suppression systems or limiting operational time, are important in different contexts, adequate ventilation is the primary concern when operating in confined spaces, where air circulation may be restricted. Additionally, effective communication through visual signals is beneficial, but it does not directly address the immediate environmental dangers posed by exhaust emissions and heat accumulation.