Which electrical component is responsible for providing power for engine starts?

The primary battery is essential in providing the necessary power to initiate engine starts. In aircraft systems, the primary battery is typically the main source of electrical energy when the engines are not running. It stores electrical energy that can be utilized to power the starter motor, which then engages the engine. The starter motor uses this stored energy to crank the engine and begin the ignition process, effectively starting the aircraft's powerplant.

While the starter motor is the component that physically cranks the engine, it relies on the electrical energy supplied by the primary battery to do so. The generator typically produces electrical power once the engine is running, and the auxiliary battery is primarily used for backup power or to start systems when needed, but it is not the primary source for engine starts in most circumstances. Understanding this hierarchy of electrical systems and their functions is crucial for comprehending how aircraft engines are started and the role that electrical components play in the process.