Which system must remain operational for generator checks?

The maintenance and operational checks of the generator are critical to ensure that the electrical systems of a vehicle or aircraft are functioning correctly. The electrical systems include the generator itself and all related components that convert mechanical energy into electrical energy and supply power to various systems.

For generator checks to be effective, the electrical systems must remain functional since these checks involve assessing the generator's output, voltage levels, current flow, and overall performance in supplying electrical power. If the electrical systems are not operational, it would be impossible to accurately perform these checks, as the generator's status cannot be assessed without the electrical system being online.

In contrast, hydraulic systems, fuel systems, and flight control systems, while essential for overall operation, do not directly impact the ability to conduct checks on the generator's output and function. Thus, the electrical systems are paramount in this context, solidifying their importance in performing generator checks.