If the APU electric fuel pump fails while running, which statement about restarting after shutdown is true?

• 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 a battery power source
• D. The APU will restart normally after maintenance

Answer: (A)

When the APU electric fuel pump fails while the APU is running, the unit can continue to operate on whatever fuel pressure remains in the system, so it won’t stop immediately. But restarting after shutdown depends on having a working fuel pressurization source. With the electric pump failed, there’s no way to pressurize fuel to the APU for a fresh start, so it cannot be restarted once you shut it down. Maintenance would be needed to replace or repair the pump before a restart is possible.