What is one of the primary functions of the Generator Control Unit (GCU) during engine start?

The Generator Control Unit (GCU) plays a crucial role during the engine start phase, particularly in monitoring the starter's performance. One of its primary functions is to keep an eye on the starter speed and to ensure that power is removed at approximately 35-40% N2. This is essential because if the starter remains engaged too long or if the engine is not starting properly, excess wear or damage can occur. By disconnecting power at this specific speed, the GCU protects the starter motor and maximizes engine performance during the critical initial moments of the engine's operation.

The other functions related to power distribution, frequency synchronization, and managing electrical loads are also important, but they are not as directly linked to the essential role of the GCU during the engine start process. Focusing on the relationship between power management and engine starting gives a clearer view of why monitoring starter speed is a priority.