What information is provided by the APU run time data display?

The APU run time data display is designed to provide crucial operational information that assists in the management and maintenance of the Auxiliary Power Unit. One of the primary functions of this display is to keep track of total operating hours, which is essential for scheduling regular maintenance and ensuring that the unit operates efficiently and safely over time. It also indicates maintenance due times, alerting the crew or maintenance personnel when the APU is approaching pre-defined service intervals.

This information is vital for predicting when maintenance will be required to prevent unexpected breakdowns, thereby enhancing reliability and performance. Understanding the total operating hours and being aware of upcoming maintenance needs allows for better planning and can contribute to the overall operational efficiency of the aircraft. The other choices do not pertain to the specific data provided by the APU runtime display and serve different purposes in aircraft operations or environmental assessment.