Which indication shows the MAX APU is running?

Which indication shows the MAX APU is running?

• A. There is no EGT gauge
• B. EGT gauge
• C. APU RUN light
• D. Fuel pressure gauge

Answer: (A)

In this MAX APU setup, what tells you the APU is running is the absence of the EGT gauge on the cockpit panel. The Exhaust Gas Temperature gauge is normally used to monitor the APU’s exhaust temperature, but when the MAX APU is operating, that gauge isn’t installed or isn’t used, so its lack of presence becomes the cue that the APU is active. It’s a design choice: the gauge isn’t required during running, so you recognize operation by the gauge not being there rather than by a reading it would display. The other indicators aren’t as reliable for this question’s context. An EGT gauge would not indicate running if it’s present, because the gauge itself is not used during operation in this configuration. A fuel pressure gauge relates to fuel supply rather than the APU’s running status, and while a RUN light can signal operation in many systems, the option here highlights the absence of the EGT gauge as the defined sign for the MAX APU running.

In this MAX APU setup, what tells you the APU is running is the absence of the EGT gauge on the cockpit panel. The Exhaust Gas Temperature gauge is normally used to monitor the APU’s exhaust temperature, but when the MAX APU is operating, that gauge isn’t installed or isn’t used, so its lack of presence becomes the cue that the APU is active. It’s a design choice: the gauge isn’t required during running, so you recognize operation by the gauge not being there rather than by a reading it would display.

The other indicators aren’t as reliable for this question’s context. An EGT gauge would not indicate running if it’s present, because the gauge itself is not used during operation in this configuration. A fuel pressure gauge relates to fuel supply rather than the APU’s running status, and while a RUN light can signal operation in many systems, the option here highlights the absence of the EGT gauge as the defined sign for the MAX APU running.