Building Your Airport5 min read
ILS & PAPI approach aids
Runway ends can carry real, working approach aids: PAPI lights for a visual glidepath, or a full ILS so aircraft can fly a guided precision approach to your runway in any weather - exactly like a real airport.
What you can install
Both aids are bought per runway end, so a single runway can have an ILS approach to one end and nothing but PAPI on the other. Select a runway and look for Approach & landing aids on its property card.
| Aid | Price per end | What you get |
|---|---|---|
| PAPI lights | ₳12,500 | Four-box PAPI on the left of the touchdown zone - red/white lights that show whether you're on the 3° glidepath. |
| ILS precision approach | ₳150,000 | CAT I ILS: localizer + 3° glideslope + DME, MALSR approach lighting with sequenced strobes, precision runway markings, edge lights - and the PAPI is included. |
The ILS package includes everything the PAPI option gives you, plus the radio approach.
All the placement engineering is automatic and follows real-world siting standards: the localizer antenna sits past the far end of the runway, the glideslope antenna abeam your touchdown zone, the beam width is tailored to your runway length, and the glidepath crosses the threshold at 50 ft. Move, stretch, or re-point the runway and the whole installation re-sites itself on the next build.
Which runways qualify
| Aid | Minimum length | Surface |
|---|---|---|
| PAPI | 500 m | Any land surface (grass strips welcome) |
| ILS | 1,000 m | Paved: asphalt, concrete, or tarmac |
Water runways can't carry approach aids.
The checkboxes stay disabled (with the reason shown) until the runway qualifies. Since an L1 Airstrip caps runways at 800 m, an ILS effectively needs at least an L2 Airfield buildable area - see Buildable area. If you later try to shrink or repave an equipped runway below the requirements, the save is blocked until you remove its aids.
Buying & removing
Aids bill once on save, like decor: the cost joins your cart total and you'll see it itemised before confirming. They're equipment rather than scenery, so they use no object slots. Removing an aid banks the unit for free re-use on another runway end; unused units refund at 50% like other equipment - see Spending.
Your ILS frequency
Every ILS is assigned its own channel in the real ILS band (108.10-111.95 MHz) plus a Morse identifier, allocated when you buy it and never changed afterwards. You'll find it in three places: the runway's property card in the builder, your airport's public page, and the runway details in the MSFS World Map. Opposite ends always get different frequencies.
Flying the approach
In the sim it works like any real ILS. Tune the frequency on NAV1, line up on final about 10 nm out at 2,500-3,000 ft above the field, and the localizer needle comes alive; intercept the glideslope from below and either hand-fly the needles or arm APRon the autopilot to couple the approach. The DME reads your distance to the touchdown zone, the MALSR strobes lead you to the threshold at night, and the PAPI confirms the same 3° path visually: two white, two red, you're right on profile.