Which action is appropriate when GNSS signals degrade or fail?

Which action is appropriate when GNSS signals degrade or fail?

• A. Cross-check navigation sources
• B. Rely on GNSS only
• C. Contact passengers
• D. Maintain current navigation and hope for recovery

Answer: (A)

When GNSS signals degrade or fail, you must not rely on GNSS as your sole navigation source. The best course is to switch to backup navigation methods and verify your position by cross-checking multiple independent references. Use conventional aids like VOR/DME, localizer/ILS, any available NDBs, and inertial navigation or dead reckoning, and corroborate what you’re seeing with ATC guidance or radar data. By comparing information from more than one source, you gain confidence in your position and maintain safe navigation while GNSS issues are resolved. This is preferable to continuing with GNSS alone, which could be unreliable, or to actions like telling passengers or simply hoping for recovery.

When GNSS signals degrade or fail, you must not rely on GNSS as your sole navigation source. The best course is to switch to backup navigation methods and verify your position by cross-checking multiple independent references. Use conventional aids like VOR/DME, localizer/ILS, any available NDBs, and inertial navigation or dead reckoning, and corroborate what you’re seeing with ATC guidance or radar data. By comparing information from more than one source, you gain confidence in your position and maintain safe navigation while GNSS issues are resolved. This is preferable to continuing with GNSS alone, which could be unreliable, or to actions like telling passengers or simply hoping for recovery.