What happens if there is a fault detected during the engine start phase?

The selection of the answer indicating that the FADEC (Full Authority Digital Engine Control) automatically aborts the start sequence is based on the designed safety and operational protocols within the A320 aircraft systems. During the engine start phase, the FADEC continuously monitors various parameters to ensure that the start is proceeding correctly. If any discrepancies or faults are detected—such as abnormal temperatures, pressures, or airflow—the FADEC is programmed to intervene and abort the start sequence to prevent potential damage to the engine or other systems.

This automated response reduces the workload for the flight crew, allowing them to focus on other critical tasks during startup while ensuring the safety and integrity of the engine operation. By automatically aborting the start, the system minimizes the risk of a failed start that could lead to more serious issues, such as an uncontained engine failure. Thus, the correct answer emphasizes the advanced control capabilities of the FADEC, which is central to the efficient operation of modern aircraft engines.