What is a potential consequence of neglecting APU maintenance?

Neglecting APU maintenance can lead to an increased risk of malfunctions. The auxiliary power unit is crucial for providing electrical power and bleed air for engine starting and for environmental control systems when the main engines are not operating. When regular maintenance is overlooked, components may wear out, systems can become less efficient, and potential issues may go unnoticed. This can eventually result in decreased performance, unexpected breakdowns, or even complete APU failure. Malfunctions can significantly disrupt operations, leading to unscheduled maintenance and operational delays, which underscores the importance of regular, proactive maintenance to ensure reliability and safety.

In contrast, the other options suggest outcomes related to better performance or efficiency, which are generally not a result of neglecting maintenance. Lower fuel consumption rates, improved operational reliability, and enhanced environmental performance are typically achieved through proper care and maintenance of the APU.