Why is regular maintenance critical for APUs?

Regular maintenance is crucial for Auxiliary Power Units (APUs) primarily to ensure safety and operational efficiency. APUs play a vital role in supplying power and air to the aircraft while on the ground, particularly before engines are started. If an APU is not maintained properly, it may fail to operate effectively, which could lead to issues such as inadequate power supply, potential engine start failures, or even safety hazards during ground operations.

Effective maintenance allows for the early identification of wear and tear or potential malfunctions in the APU. This proactive approach helps to mitigate risks posed to the aircraft and its crew, ensuring that the APU functions reliably when needed. Furthermore, regular checks and servicing contribute to the overall efficiency of aircraft operations, as a well-maintained APU can minimize fuel consumption and operational costs.

In contrast, the other options—such as increasing fuel production, reducing mechanical failure in airframes, and extending operational range—do not directly relate to the primary functions or purposes of APU maintenance, making them less relevant in this context.