Which instrument displays the Flight Director Bar on a conventional ADI?

• A. Flight Director Computer
• B. EADI
• C. HSI
• D. NAV/COM

Answer: (A)

The pickup here is that the Flight Director Bar is a guidance cue that shows the commanded attitude to fly, and its data comes from the Flight Director Computer. In a conventional ADI setup, the Flight Director Computer processes inputs from the flight guidance system and autopilot to generate the necessary pitch and bank commands, which are then displayed as the FD Bar on the Attitude Indicator. The EADI is simply the attitude display, but in this context it’s the source of the bar’s movement that comes from the FD Computer, not the instrument itself. The HSI or NAV/COM deal with heading and radio navigation, not the flight director cues. So the instrument responsible for displaying the Flight Director Bar in a conventional ADI is the Flight Director Computer.