Which system is powered by the Primary 26V AC BUS?

The Pitch Trim Position system is powered by the Primary 26V AC BUS because it requires a constant and reliable source of power to ensure that the aircraft's pitch trim function operates accurately and responsively. This system is essential for stabilizing the aircraft in flight, allowing for adjustments to the aircraft's attitude without the need for constant input from the pilot. The reliable functioning of pitch trim directly affects flight safety and performance, making it critical to have its power sourced from the Primary 26V AC BUS, which is designed to supply power to essential flight systems.

While other systems present in the aircraft, such as the Flap Position Indicator and Navigation System, have their own dedicated power sources or may depend on different electrical buses, the specific requirement for constant pitch adjustments justifies the use of the 26V AC BUS for the pitch trim system. Understanding the electrics of the aircraft and how they power various components is crucial for safe operation and maintenance.