Which of the following is NOT listed as a possible warning flag on a conventional (non EFIS) ADI?

• A. BARO
• B. GS
• C. GYRO
• D. LOC

Answer: (A)

Warning flags on a conventional ADI indicate when the attitude data may be unreliable. The attitude indicator relies on a gyro; if the gyro data aren’t valid, a warning flag like GYRO would appear to alert the pilot that the horizon is no longer trustworthy. Glideslope and localizer are part of the ILS navigation displays, not the attitude indicator itself, so they aren’t represented as warning flags on a plain ADI. The barometric reference, used by the altimeter rather than the attitude indicator, isn’t a source of attitude data and therefore isn’t shown as a warning flag on a conventional ADI. So BARO wouldn’t be listed as a warning flag on a traditional non-EFIS ADI.