What is the procedure if you lose navigation data during an approach on the Longitude 700?

• A. Abort the approach and go to missed approach immediately
• B. Fly the approach with raw data, use backup navigation sources, contact ATC, and follow the QRH guidance
• C. Continue visually and ignore navigation data
• D. Switch to GPS-only guidance and descend

Answer: (B)

When navigation data is lost during an approach, the safe path is to fly the approach using raw data from the aircraft’s instruments and any available backup navigation sources, while coordinating with ATC and following the QRH abnormal procedures. This approach keeps you grounded in verified information—using the localizer/Glideslope indications, altimeter, air data, and any standby nav aids you still have—and it leverages secondary navigation sources to maintain situational awareness and proper course guidance. The QRH provides the standardized steps for this exact situation, ensuring you use approved procedures rather than relying on potentially compromised primary data. Aborting immediately or continuing visually without nav data can be unsafe, and switching to GPS-only guidance may not be appropriate or reliable in the loss of nav data scenario. Following the QRH guidance gives you a structured path to either complete the approach with backup sources or execute a missed approach if required.