Microsoft Flight Simulator 7 min read

How do I position an ILS glideslope in MSFS 2024 SDK?

Ian Stephens
In short

Learn to position an ILS glideslope in the MSFS 2024 SDK, set its course, pitch and elevation, then fix wrong or missing captures.

To position an ILS glideslope in the MSFS 2024 SDK, attach the ILS to the correct runway end, enter its frequency, ident and front course, add the glideslope, then place its transmitter beside the runway near the touchdown zone. Set its surveyed elevation and published glide angle, build the package and test capture from below.

ILS components and positioning logic

An ILS is airport facility data, not merely a visible antenna model. In the airport data generated by the SDK, the runway end's <Ils> record contains its <GlideSlope> data. Placing a mast as a scenery object does not create a radio signal, and an ILS can work without a visible mast.

If the airport package does not yet exist, our airport-project workflow from Developer Mode through package testing covers the surrounding SDK process. Authoring and compiling an MSFS 2024 SDK package requires the Windows PC version; consoles are not SDK authoring environments.

ComponentWhat it controlsNormal position or data
LocaliserLateral course guidanceBeyond the far end of the runway on its extended centreline; frequency, ident, front-course heading and range
GlideslopeVertical guidanceBeside the runway, down-runway from the landing threshold; latitude, longitude, MSL elevation, pitch and range
DMESlant-range distanceOptional paired facility with its own position; it is not created automatically by the glideslope
Approach procedureSelectable FMS or flight-planner procedureSeparate procedure data; creating the radio facility alone does not guarantee an approach will appear

The glideslope is paired with the localiser channel. The pilot tunes the localiser frequency; there is no separate cockpit glideslope frequency to enter.

How do I add and position the glideslope?

  1. Correct the runway first. Confirm both threshold coordinates, elevation, true runway heading and designators. The runway number multiplied by ten is only a rounded magnetic direction, not a reliable geometric heading.
  2. Select the intended runway end. In the runway properties, add or enable the ILS for the end being approached. Primary and secondary are runway-data associations, not indications of which runway is active, so verify the displayed designator and inbound direction.
  3. Enter the localiser data. Set the published ident, frequency, front course, magnetic variation and useful range. Airport geometry uses true headings, while charts normally show magnetic courses; follow the field's documented convention and convert rather than copying a magnetic course into a true-heading field.
  4. Position the localiser. Use surveyed coordinates where available. For a fictional airport, put it beyond the opposite threshold on the extended centreline, with the front course pointing inbound towards the landing runway. Do not place it at the approach threshold or use the reciprocal course.
  5. Add the glideslope component. Expand the runway end's ILS properties and add or enable its glideslope. The property layout can move between SDK releases, but the data relationship remains runway end, ILS, then glideslope.
  6. Place the glideslope transmitter. Enter its surveyed latitude and longitude. It normally sits laterally beside the runway and some distance beyond the landing threshold in the direction of touchdown. Do not put it on the centreline, at the threshold or automatically at the PAPI position.
  7. Set the vertical data. Enter the transmitter reference elevation as MSL, converting any source given as height above ground. Set the published glide angle—commonly, but not universally, 3 degrees—and a sensible published or operational range using the units shown by the SDK.
  8. Build and reload the package. Save the scenery, compile the package and reload the airport or flight. If the old facility remains active, restart Microsoft Flight Simulator 2024 so its navigation data is reloaded; moving a marker in the editor is not proof that the radio facility has refreshed.

When modifying a stock airport, use the Airport object's deletion or replacement controls only for records you recreate. Leaving the original facility active can produce two localisers, while indiscriminately deleting approaches can remove the procedures pilots expect to find in the FMS.

How do I calculate the correct glideslope position?

For a real airport, published facility coordinates and elevation take precedence over a calculated approximation. If the ILS is fictional, use the intended threshold-crossing height to check the geometry rather than placing the transmitter by eye.

Threshold-crossing height ≈ (horizontal plan distance × tan(glide angle)) + (glideslope elevation − threshold elevation)

Measure the plan distance from the glideslope transmitter to the threshold reference point on the runway centreline, so its lateral offset is included. At a 3-degree angle, every 1,000 feet of level plan distance contributes about 52 feet of height.

  • If the path crosses the threshold too high, check for an antenna positioned too far down the runway, excessive transmitter elevation or an angle that is too steep.
  • If it crosses too low, check for an antenna too close to the threshold, an elevation entered as AGL instead of MSL or an angle that is too shallow.
  • Correct coordinate, unit and elevation errors before altering a published glide angle merely to make the cockpit indication look right.

Our explanation of how localiser and glideslope signal geometry behaves provides the underlying interception and threshold-crossing logic.

How should I test the ILS in MSFS 2024?

  1. Remove competing airport packages. Test with only the package being developed and the navigation data required by the simulator. Duplicate airport or navaid records can disguise an otherwise correct edit.
  2. Approach from the front-course side. Start outside the normal intercept area, aligned close enough to receive the localiser and below the calculated glideslope. A back-course approach should not be used to validate vertical guidance.
  3. Tune and identify the localiser. Confirm the frequency, ident and inbound course before assessing the glideslope. Capture the localiser first, then intercept the glideslope from below.
  4. Check the complete path. Verify that the glideslope becomes active at a useful distance, centres near the expected intercept point and crosses the threshold at the intended height without commanding an obviously displaced touchdown.
  5. Repeat after a clean reload. Test another NAV-capable aircraft if necessary. This separates scenery-data faults from an individual aircraft's avionics or autopilot behaviour.

For the airborne portion, use our practical MSFS 2024 ILS flight check to confirm tuning, localiser capture and glideslope interception.

Why does the new glideslope not work correctly?

SymptomLikely causeFix
No localiser or glideslopePackage not loaded, wrong runway end, incorrect frequency, insufficient range or stale navigation dataInspect the runway association, rebuild, reload the flight and verify that the compiled package is active
Localiser works but no glideslope appearsMissing glideslope child record, invalid pitch or range, back-course reception, or interception from aboveCheck the nested glideslope data and perform a front-course intercept from below
Localiser indication is reversedReciprocal heading or ILS attached to the opposite primary/secondary endSet the inbound front course and associate it with the landing runway end
Glideslope is consistently high or lowWrong latitude, longitude, elevation units or pitchRecheck surveyed data and use the threshold-crossing calculation before changing the angle
Signal points towards another runwayDuplicate stock, package or navigation-data facilityRemove the duplicate during testing and apply narrowly targeted airport replacement settings
ILS works but is absent from the FMSNo matching approach procedure, or the procedure data uses a different runway or identAdd or correct the separate approach record; repositioning the transmitter will not create a procedure
Antenna is visible but radios receive nothingOnly a scenery model was placedCreate the runway-associated ILS and glideslope facility data

If the receiver shows a plausible signal from the wrong direction or runway, check our breakdown of wrong-runway and false-signal causes. Duplicate facilities, incorrect end associations and capturing above the normal glideslope are the faults we see most often.

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