If the APU electric fuel pump fails while the APU is running, what happens?

• A. The APU will continue to run, but it will not start once it is shutdown
• B. The APU will shut down immediately and cannot restart
• C. The APU will automatically switch to battery power
• D. The APU will run normally with no issue

Answer: (A)

The issue tests how the APU fuel supply behaves when the electric fuel pump fails during operation. When the APU is already running, it can keep operating on the fuel already in its lines or on an alternate feed, so the unit doesn’t immediately shut down just because that electric pump failed. However, that pump is essential for starting and re‑starting the APU. If you shut the APU down, there’s no pump available to prime and deliver fuel for a fresh start, so it cannot be restarted until the pump problem is fixed. This is why the APU would continue to run but would not be able to restart after shutdown. It does not switch to battery power, and running normally with no issue isn’t accurate because starting/restarting depends on that fuel-pump supply.