If you lose primary navigation data during flight, what is the recommended handling on the Longitude 700?

• A. Use standby navigation modes, revert to raw data if needed, follow approach procedures with alternative guidance, inform ATC/dispatcher
• B. Continue with current route until destination
• C. Switch to autopilot navigation
• D. Land immediately

Answer: (A)

When the primary navigation data is lost, the flight must rely on independent, validated sources and procedures rather than the failed system. Using standby navigation modes taps into alternative, uncorrupted sources that stay associated with the aircraft’s navigation backbone. If needed, reverting to raw data means reading the navigation indications directly from the standby systems rather than from the fused, potentially unreliable display, helping you determine your position and course with confidence. Following approach procedures with alternative guidance ensures you can continue toward the approach using backup guidance (such as VOR/LOC or other non-primary sources) while maintaining situational awareness. Communicating with ATC or the dispatcher is essential so they know your nav status and can assist with vectors, alternatives, and expected fixes.

Continuing on the current route without reliable navigation, switching to autopilot navigation, or landing immediately without a safe plan are not appropriate responses to a primary navigation data loss, as they either rely on an unreliable source, bypass the required backup procedures, or rush to an unsafely abrupt decision.