Learn what Use Calculated ILS Signals changes in the FlyByWire A32NX, when to enable it, and how to fix localiser or glideslope faults.
In Microsoft Flight Simulator, Use calculated ILS signals makes the FlyByWire A32NX compute localiser and glideslope guidance from the aircraft’s position and the ILS facility geometry available to it, instead of using MSFS’s native receiver deviations. It changes the signal source; it does not tune the ILS, select an approach or arm APPR.
What changes when calculated ILS signals is enabled?
With the setting enabled, the A32NX’s radio-navigation logic determines ILS signal validity and deviation using its own geometry calculations.
| Setting | Signal source | Practical effect |
|---|---|---|
| Enabled | A32NX-calculated localiser and glideslope data | Signal acquisition, validity and deviation are based on the aircraft’s calculated relationship to the ILS facility. |
| Disabled | Native MSFS navigation-receiver data | The A32NX uses the localiser and glideslope values reported directly by the simulator. |
Because the two sources model reception differently, they may acquire or lose the signal at different points, particularly near the edge of coverage or behind the transmitter. An ILS contains separate localiser and glideslope components, explained in our guide to ILS signals and frequency ranges.
Both modes still require a valid ILS facility and correct tuning, either automatically through the flight-management system or manually through the MCDU. Calculated mode cannot create an ILS for a runway that has none, add a glideslope to a localiser-only approach, or convert an RNAV approach into an ILS.
Should I enable Use calculated ILS signals?
Leave the setting at the aircraft package’s default when ILS guidance works correctly; change it when diagnosing a repeatable reception or alignment problem.
- Enable it when the aircraft is correctly tuned but the native MSFS signal is erratic, selects an implausible beam or remains available outside sensible coverage.
- Disable it when calculated mode produces a missing or displaced localiser at a particular airport while the native receiver aligns correctly.
- Do not expect either mode to fix bad data. If the runway, ILS transmitter or approach record is misplaced, switching sources may only reveal the mismatch.
The default and exact implementation can differ between package branches. Our explanation of how A32NX Stable and Development builds differ will help if another pilot’s settings or behaviour do not match yours.
Why is the localiser or glideslope missing?
A missing ILS indication is usually caused by the selected approach, tuning, interception geometry or airport data rather than this setting alone.
- Confirm the runway and approach type. Check that the approach serves the correct runway direction and includes both localiser and glideslope guidance. Opposite runway ends can use different frequencies or have different approach equipment.
- Verify the tuned station. Check the ILS frequency, course and identifier shown by the A32NX. A flight plan containing an ILS approach does not guarantee that the expected facility has been tuned and identified.
- Use a valid intercept. Approach the localiser from the front, at a sensible intercept angle, and intercept the glideslope from below. Our MSFS 2024 ILS capture procedure covers the normal setup and sequence.
- Check for airport-data conflicts. Updated or duplicate airport scenery can disagree with the navigation facility data, producing an offset beam or no usable signal. A problem confined to one runway or airport strongly suggests a data mismatch.
- Compare both signal sources. Repeat the same approach with the option enabled and disabled. If neither source works, continue with the receiver, navigation-source and scenery checks in our flight-simulator IFR troubleshooting guide.
Does the setting affect autopilot ILS capture?
Yes, indirectly: the autopilot and flight directors respond to whichever localiser and glideslope deviations the selected signal source provides.
The setting does not arm the approach modes or change their capture logic. On the flight mode annunciator, LOC and G/S should first appear armed and then change to captured modes. The LS pushbutton displays the ILS scales and identification; it does not tune the receiver or arm APPR.
If stable diamonds are visible but the aircraft will not capture them, investigate the APPR mode, intercept angle and altitude rather than repeatedly changing the calculated-signals option. If the localiser captures but the glideslope does not, the common mistake is arriving above the glideslope or flying an approach without vertical ILS guidance.