If the ECAM APU page is not displayed, what other indication shows that the APU is running?

If the ECAM APU page is not displayed, what other indication shows that the APU is running?

• A. The green AVAIL light in the start pushbutton comes on
• B. The APU control page appears on ECAM
• C. The APU exhaust temperature gauge shows normal range
• D. The APU START button lights amber

Answer: (A)

The indicator that directly shows the APU is running without relying on ECAM is the green AVAIL light in the APU start pushbutton. When the APU is running, this light comes on, giving you a quick, unambiguous cue that the APU is active even if the ECAM APU page isn’t displayed. The other signs are less direct: the ECAM page would show APU status if it’s available, but you’re assuming that page isn’t shown; the APU exhaust temperature gauge could be read to infer running but isn’t as immediate or explicit; and the amber light on the Start button usually indicates start in progress or a fault, not normal running.

The indicator that directly shows the APU is running without relying on ECAM is the green AVAIL light in the APU start pushbutton. When the APU is running, this light comes on, giving you a quick, unambiguous cue that the APU is active even if the ECAM APU page isn’t displayed.

The other signs are less direct: the ECAM page would show APU status if it’s available, but you’re assuming that page isn’t shown; the APU exhaust temperature gauge could be read to infer running but isn’t as immediate or explicit; and the amber light on the Start button usually indicates start in progress or a fault, not normal running.