What maintenance practice is essential for the APU?

Regular visual inspections for leaks are essential for the APU (Auxiliary Power Unit) maintenance because they help to identify any potential issues that could lead to failures or safety hazards. The APU is critical for starting the main engines and powering essential systems when the aircraft is on the ground. If there are leaks in the fuel or oil systems, it can lead to dangerous conditions such as fires or engine malfunctions.

Visual inspections focus on detecting signs of wear or damage, including fluid leaks, which can indicate problems with seals, hoses, or other components. By catching these issues early, you can address them before they develop into more serious problems, thus ensuring the reliability and safety of the APU. This preventive measure is a key part of maintaining overall aircraft performance and operational readiness.

While other maintenance practices, such as refueling and mechanical replacements, are important, they do not replace the critical nature of regular visual inspections in identifying and mitigating issues that could lead to failure during operation.