What does the "Main" bus supply power to?

The "Main" bus in an aircraft is designed to supply power to all systems that are not covered by other specific buses. This includes a wide range of systems such as non-essential flight instruments, avionics, lighting, and other equipment that is critical for regular flight operations.

In a multi-engine aircraft, the electrical distribution system is divided into several buses to manage power effectively and ensure that important systems remain operational even if one bus fails. The Main bus acts as the primary power source for systems that do not have dedicated buses, providing flexibility and redundancy.

While essential flight instruments and emergency systems are vital, they are typically supplied power by dedicated buses for reliability reasons. Other systems like Com 2 and NAV 2 may also have their own buses to ensure that communication and navigation capabilities remain operational independently of the Main bus. Therefore, stating that the Main bus powers all systems not covered by other buses accurately reflects its role in the aircraft's electrical system.