GPS vs radio navigation in a flight simulator: learn which to use by procedure and aircraft, plus how to avoid source-selection errors.
Use GPS for modern en-route flying, direct routing and RNAV procedures; use radio navigation for VOR, NDB, localiser and ILS procedures, vintage aircraft, and raw-data practice. In a flight simulator, the right choice is the source required by the chart and supported by the aircraft—not simply the easiest display.
In Aviation & Real-World Flying practice, this is a procedure-and-equipment decision. GPS uses satellite-derived position data and a navigation database, while VOR, NDB, DME, localiser and glideslope systems depend on ground transmitters. Our explanation of how aircraft navigation systems derive position and guidance covers those underlying differences.
GPS vs radio navigation at a glance
Use GPS for area navigation and the appropriate radio receiver whenever a route or procedure is defined by a ground-based aid.
| Flight or procedure | Primary source | Reason |
|---|---|---|
| Direct routing or an RNAV flight plan | GPS or FMS | It sequences waypoints and provides continuous track guidance without flying directly between ground stations. |
| RNAV (GPS) or supported RNP procedure | GPS or FMS | The procedure depends on area-navigation capability and a suitable database. |
| VOR airway or VOR approach | NAV receiver | The course is defined by a VOR radial rather than the GPS flight-plan line. |
| NDB procedure | ADF receiver | The bearing indication comes from the NDB signal. |
| ILS or localiser final approach | NAV/LOC receiver | The localiser and glideslope provide the final approach guidance. |
| VFR pilotage | Visual references, with GPS as an aid | GPS improves awareness, but it should not replace looking outside when practising realistic VFR navigation. |
| Historic aircraft or raw-data training | Radio navigation | It matches the fitted equipment and builds course-interception, tracking and position-fixing skills. |
A simulator may let an aircraft perform navigation it would not be approved or equipped to use in real life. A moving map alone does not make an installation suitable for IFR GPS or RNP operations. For realistic training, follow the aircraft documentation, chart notes and available avionics.
How do I choose the correct navigation source?
Choose the source named by the route or approach, then verify that the HSI, CDI and autopilot are following that same source.
- Read the procedure title and notes. RNAV (GPS) normally calls for GPS/FMS guidance; VOR, NDB, LOC and ILS procedures call for the corresponding receiver on the controlling segment. Naming conventions vary by country and data cycle, so do not decide from the map alone.
- Confirm the aircraft's capability. Some GPS units provide only en-route navigation, while others support approaches and vertical guidance. RNP procedures can demand capabilities that a basic panel-mounted GPS does not simulate.
- Select the CDI or HSI source. Look for an annunciation such as
GPS,NAV1,VLOCorLOC. Labels vary between avionics, but the displayed source must match the guidance you intend to follow. - Set up radio aids properly. Put the frequency in the active window, select the correct receiver, listen to or verify the identifier where modelled, and set the required course. Our guide to tuning, identifying and tracking VOR and NDB stations covers the practical technique.
- Check the automation before capture. Confirm the lateral source, desired course and autopilot mode. On many aircraft,
NAVfollows the selected lateral source, whileAPRorAPPis needed to capture an ILS glideslope.
Which is more accurate in a flight simulator?
GPS usually provides the more precise and continuous displayed position, but greater accuracy does not make it the correct source for every procedure. A VOR, localiser or NDB procedure is designed around the behaviour and limitations of that radio aid.
Radio signals can be limited by range, altitude, terrain and station geometry. VOR guidance also becomes increasingly sensitive close to the station, while an NDB bearing may be less stable depending on how deeply the simulator models signal effects. GPS errors more often come from an incorrect active leg, a route discontinuity, outdated navigation data or the wrong CDI source.
Common source-selection failures
Most apparent navigation failures are setup errors rather than failed instruments.
- The magenta route is visible but the aircraft ignores it: select GPS as the CDI source, confirm the correct leg is active, and check that the autopilot is in a lateral navigation mode.
- An ILS is tuned but no localiser appears: verify the active frequency, correct NAV receiver, reception range and a
VLOC,NAVorLOCsource rather than GPS. - The VOR needle remains flagged: check the station identifier, line-of-sight range, aircraft altitude and navigation database. For simulator-specific faults, use our checklist for diagnosing missing VOR reception in Microsoft Flight Simulator.
- The GPS skips a waypoint or turns unexpectedly: inspect the active leg, remove any route discontinuity and check whether a manual course or vector leg requires pilot action.
Can I use GPS for an ILS approach?
Use GPS to reach the initial or intermediate approach fixes, but use the localiser and glideslope as the final guidance for an ILS. Some integrated avionics switch automatically from GPS to localiser capture; others require a manual source change, so verify the displayed annunciation rather than assuming it happened.
The opposite applies on an RNAV (GPS) approach: remain on the GPS/FMS source. LPV or other satellite-based vertical guidance may resemble an ILS display, but it is not a localiser and does not require switching to NAV1. We explain the GPS-versus-NAV source change for an ILS in more detail.
How should beginners practise GPS and radio navigation?
Beginners should learn both systems separately before combining them on one flight.
- Fly a short route using GPS. Practise selecting a waypoint, intercepting the programmed track and recognising the active-leg and CDI-source indications.
- Repeat the route using VOR or VOR/DME. Tune and identify each station, intercept a radial and note how range and geometry affect the indication.
- Combine the systems on an approach. Use GPS for en-route guidance and the arrival, then switch to the required radio source before an ILS or VOR final approach.
The practical rule is simple: use GPS for GPS/RNAV work, use the named radio aid for radio procedures, and cross-check both when the aircraft carries both. During realistic VFR practice, keep visual references primary and treat the moving map as supporting information.