What are ground checks?

• A. Checks performed on the ground using a power unit
• B. In-flight checks during engine run
• C. Visual inspections during taxi
• D. Post-flight checks

Answer: (A)

Ground checks are tests done with the aircraft on the ground using a power source (like a ground power unit or an APU) to run systems and verify their operation before flight. This lets mechanics start engines, test electrical, hydraulic, fuel, and environmental systems, and check indications without actually taking the aircraft into the air. It’s distinct from in-flight checks (performed during flight with engines running), visual/starts during taxi, or post-flight checks done after landing.