Why are both igniters powered during the ENG 1 start sequence?

During the ENG 1 start sequence, both igniters are powered to ensure reliability and successful ignition of the engine. This redundancy is vital, especially during the critical start phase when successful engine ignition is necessary to ensure safe operation. The powered igniters provide the necessary spark to ignite the fuel-air mixture within the engine combustor.

When the start lever is moved to the start position, the system activates both igniters to maximize the chances of achieving a consistent and stable start. This practice is in line with safety protocols, as it minimizes the risk of a failed start, which can occur if only one igniter is engaged. By utilizing both igniters during the start, the aircraft maintains heightened operational integrity.

While other reasons may seem plausible, they do not accurately reflect the procedure in place for an A320 engine start. The choice of using both igniters as a standard ensures a robust engine start procedure under various conditions.