What is the primary advantage of using an electric turn coordinator in an aircraft with a vacuum system for gyroscopic instruments?

The primary advantage of using an electric turn coordinator in an aircraft equipped with a vacuum system for gyroscopic instruments is that it provides redundancy in case of vacuum system failure. In many aircraft, critical flight instruments such as the attitude indicator and heading indicator rely on a vacuum system to operate effectively. If the vacuum system experiences a failure, these instruments can become inoperative, which could severely impair the pilot's situational awareness.

By incorporating an electric turn coordinator, pilots gain a backup system that continues to function independently of the vacuum system. This redundancy is crucial for maintaining safe operational standards, ensuring that the pilot can still accurately monitor the aircraft’s turn and bank information even if the primary instruments fail due to a vacuum issue. This aspect of redundancy enhances safety and reliability in the aircraft's instrumentation, making it a vital feature in modern aviation.