What does Avionics Bus 1 include in a Cessna 172?

Avionics Bus 1 in a Cessna 172 is essential for providing power and connectivity to critical flight displays and systems. The Primary Flight Display (PFD) is a key component of the flight instrumentation, providing vital information such as speed, altitude, and attitude. The inclusion of the PFD cooling fan is also noteworthy since the fan helps to maintain an optimal operating temperature for the PFD, ensuring that it functions reliably during flight.

This configuration supports the aircraft's capacity to present crucial flight data directly to the pilot, thereby enhancing situational awareness and safety. The PFD and its cooling system are designed to work together, ensuring that the display remains visible and functional even under demanding conditions.

The other choices like Comm 2, Transponder, and Flight Information System are part of different buses or systems within the aircraft, not specifically under Avionics Bus 1, which further emphasizes the importance of understanding the allocation of avionics systems in the Cessna 172.