FSX autopilot won’t intercept the localizer on approach (flies right past)

FSX ILS/LOC capture – why the AP flies right through

This is a really common FSX autopilot setup issue. In FSX the AP will follow whatever lateral “source” it’s actually coupled to, and it also isn’t very forgiving if you try to blast across the beam at a steep angle and high speed.

Step-by-step: a reliable way to get LOC capture in FSX

1. Tune NAV1 to the ILS (and make sure it’s alive)
   Set NAV1 to the runway’s ILS frequency. You should see the LOC needle start to move as you get in range. If the needle stays dead, you’re not receiving the ILS yet (wrong freq, too far, wrong runway, etc.).

2. Make sure the airplane is in NAV mode (not GPS) for the CDI
   A lot of FSX aircraft (default and add-on) have some form of NAV/GPS switch. If it’s still set to GPS, the AP will happily ignore the localizer even if you press APP. For ILS work, you want it on NAV1.

3. Intercept from a shallow angle using HDG mode
   Use HDG to bring yourself onto the localizer at roughly a 20–30° intercept. If you try to intercept at 60–90°, the default AP often “sees” it too late and you sail through.

4. Be stabilized and not too fast
   If you’re doing 180–220 knots in something that really should be 120–160 on final, the capture happens late and overshoots are common. Get slowed and configured before the needle centers.

5. Arm APP at the right time
   Stay in HDG mode until the LOC needle starts coming in (you can see it moving toward center), then press APP and leave it alone. If you keep twisting the heading bug or hand-flying against it right as it’s trying to capture, it may never settle.

6. Altitude: intercept the glideslope from below
   For a full ILS, level off below the GS so the GS needle is above you, then arm APP. If you’re already above the glideslope when you arm it, FSX can act weird (sometimes it’ll take LOC but never GS, sometimes it struggles with both).

Two extra “gotchas” that bite people in FSX

• Make sure you’re intercepting the front course. Coming at the localizer from the back side can give confusing indications and unreliable capture behavior.
• If you used GPS to navigate toward the airport, don’t forget the “GPS-to-NAV” changeover before you expect the ILS to work.

Quick questions so we can pin down what’s happening on your setup

• Which aircraft are you flying (default C172/737, or a specific add-on)?
• Are you pressing NAV or APP when you want it to capture?
• Do you have a NAV/GPS switch (or similar), and is it definitely set to NAV1 at the time?
• Roughly what intercept angle/speed are you at when you cross the localizer?
• What airport/runway (or at least the ILS frequency/course) are you trying this on?