If RAIM is degraded but GPS is still functional, what is the recommended action?

• A. Ignore and proceed with GPS
• B. Continue with GPS and try to regain RAIM
• C. Use alternate navigation methods and continue to monitor GPS
• D. Fly visually without reference

Answer: (C)

When RAIM is degraded, you can still receive GPS data, but you can’t rely on its position integrity for navigation or approaches. The proper action is to use alternate navigation methods (such as VOR, DME, localizer, or cross-checks) and continue to monitor the GPS status. This keeps you from over‑relying on an potentially unreliable GPS while you maintain situational awareness and watch for any improvement in RAIM or further degradation. Ignoring the degraded RAIM and pressing on with GPS risks an undetected position error, and trying to “regain” RAIM by continuing flight isn’t guaranteed. Flying visually without reference isn’t appropriate for instrument conditions.