When the cowl anti-ice system is engaged, what must also be considered?

When the cowl anti-ice system is engaged, it is essential to select continuous ignition. This is because the use of the cowl anti-ice system can lead to ice formation on the aircraft, particularly in conditions with moisture in the atmosphere. Engaging continuous ignition helps to ensure that the engines are protected from potential flameouts that can occur when ice or snow is present in the airflow into the engine.

Selecting continuous ignition activates the engine's ignition system continuously, which maintains a stable combustion process. This is particularly important when operating in icing conditions, as it mitigates the risk associated with ice and ensures the engines operate reliably.

In contrast, the other options do not align with the operational requirements regarding the use of the cowl anti-ice system. For instance, turning off all other systems would be impractical and unnecessary for safe operation. The cowl anti-ice system is not restricted to ground use only, as it can be activated during flight conditions that warrant its use. Lastly, the statement that neither is necessary based on conditions doesn't account for the importance of continuous ignition in maintaining engine performance and safety in potential icing conditions.