During an unreliable airspeed condition, which sequence involving autopilot and flight directors is recommended?

During an unreliable airspeed condition, which sequence involving autopilot and flight directors is recommended?

• A. Autopilot - DISENGAGE; FDs - DESELECT; Use ISI for pitch reference
• B. Autopilot - ON; FDs - ON; Use ISI for pitch reference
• C. Autopilot - DISENGAGE; FDs - KEEP ON; Ignore ISI
• D. Autopilot - ON; FDs - DESELECT; Ignore ISI

Answer: (A)

When airspeed data cannot be trusted, you want to remove automatic guidance and rely on a stable, manual reference rather than follow faulty cues. Disengaging the autopilot stops automated flight corrections that would chase erroneous speed readings. Deselecting the flight directors eliminates guidance cues that might be based on the same unreliable data, reducing cockpit confusion. Use the ISI as your pitch reference to maintain attitude with a source that remains stable despite the airspeed issue. This combination gives you direct control of the aircraft and a trustworthy reference for pitch, helping you stay safe until reliable airspeed data is restored.

When airspeed data cannot be trusted, you want to remove automatic guidance and rely on a stable, manual reference rather than follow faulty cues. Disengaging the autopilot stops automated flight corrections that would chase erroneous speed readings. Deselecting the flight directors eliminates guidance cues that might be based on the same unreliable data, reducing cockpit confusion. Use the ISI as your pitch reference to maintain attitude with a source that remains stable despite the airspeed issue. This combination gives you direct control of the aircraft and a trustworthy reference for pitch, helping you stay safe until reliable airspeed data is restored.