What is the difference between a VOR approach and a GPS (RNAV) approach?

What is the difference between a VOR approach and a GPS (RNAV) approach?

• A. VOR approaches rely on satellite navigation and may include vertical guidance.
• B. VOR approaches use ground signals but RNAV uses satellites.
• C. VOR approaches rely on ground-based VOR signals and published procedures; RNAV uses satellite navigation with potential vertical guidance and more direct routing.
• D. RNAV approaches require no navigation signals.

Answer: (C)

The key idea here is how the navigation signals and the resulting approach paths differ between VOR and RNAV approaches. A VOR approach uses ground-based VOR signals to determine position and fly the published procedure. You tune a VOR ground station, follow its radial to the final approach course, and use any accompanying DME distance to help with sequencing. This kind of approach provides lateral guidance only and does not offer vertical guidance in the standard VOR approach; you fly the published altitudes and descend as allowed, but there isn’t an integrated vertical guidance path like a glideslope. RNAV approaches, on the other hand, rely on satellite navigation. Your position is determined by GPS (or other GNSS) and the flight management system or autopilot guides you along a sequence of waypoints. Because RNAV can use precise position data from satellites, it can provide vertical guidance in the form of LPV or LNAV/VNAV and allows more direct routing between fixes, not being limited to a chain of VOR radials. Some RNAV approaches even permit curved or more flexible tracks that aren’t tied to ground-based stations. So the best answer captures both ideas: VOR approaches depend on ground-based VOR signals and published procedures, while RNAV approaches use satellite navigation and can offer vertical guidance and more direct routing.

The key idea here is how the navigation signals and the resulting approach paths differ between VOR and RNAV approaches. A VOR approach uses ground-based VOR signals to determine position and fly the published procedure. You tune a VOR ground station, follow its radial to the final approach course, and use any accompanying DME distance to help with sequencing. This kind of approach provides lateral guidance only and does not offer vertical guidance in the standard VOR approach; you fly the published altitudes and descend as allowed, but there isn’t an integrated vertical guidance path like a glideslope.

RNAV approaches, on the other hand, rely on satellite navigation. Your position is determined by GPS (or other GNSS) and the flight management system or autopilot guides you along a sequence of waypoints. Because RNAV can use precise position data from satellites, it can provide vertical guidance in the form of LPV or LNAV/VNAV and allows more direct routing between fixes, not being limited to a chain of VOR radials. Some RNAV approaches even permit curved or more flexible tracks that aren’t tied to ground-based stations.

So the best answer captures both ideas: VOR approaches depend on ground-based VOR signals and published procedures, while RNAV approaches use satellite navigation and can offer vertical guidance and more direct routing.