What maintenance actions are typically performed on an APU to ensure reliability?

What maintenance actions are typically performed on an APU to ensure reliability?

• A. Regular oil changes and filter changes, fuel filter maintenance, bleed air checks, electrical system checks, intake/exhaust inspection, and periodic borescope or overhauls as required.
• B. Cosmetic cleaning only.
• C. Replacing the entire APU every year.
• D. No maintenance required.

Answer: (A)

Maintaining an APU to ensure reliability means performing a set of regular actions that protect lubrication, fuel, air, and electrical systems and watch for wear inside the turbine. Regular oil changes and filter changes keep lubrication effective and remove particulates; fuel filter maintenance prevents contaminants from entering the fuel system and combustor; bleed air checks ensure the bleed system delivers correct pressure and has no leaks, which is essential for pneumatic systems and anti-ice. Electrical system checks verify the health of starters, generators, sensors, wiring, and controls so a fault doesn’t cascade into a failure. Intake/exhaust inspection catches damage, obstructions, or fouling that would restrict airflow or cause overheating. Periodic borescope inspection or engine overhauls as required allow direct assessment of the hot section for cracks, wear, and deposits, with parts replaced as needed to meet limits. Cosmetic cleaning does not improve reliability, replacing the entire APU each year is unnecessary, and no maintenance would obviously compromise reliability.

Maintaining an APU to ensure reliability means performing a set of regular actions that protect lubrication, fuel, air, and electrical systems and watch for wear inside the turbine. Regular oil changes and filter changes keep lubrication effective and remove particulates; fuel filter maintenance prevents contaminants from entering the fuel system and combustor; bleed air checks ensure the bleed system delivers correct pressure and has no leaks, which is essential for pneumatic systems and anti-ice. Electrical system checks verify the health of starters, generators, sensors, wiring, and controls so a fault doesn’t cascade into a failure. Intake/exhaust inspection catches damage, obstructions, or fouling that would restrict airflow or cause overheating. Periodic borescope inspection or engine overhauls as required allow direct assessment of the hot section for cracks, wear, and deposits, with parts replaced as needed to meet limits. Cosmetic cleaning does not improve reliability, replacing the entire APU each year is unnecessary, and no maintenance would obviously compromise reliability.