How do I fly an ILS approach in FlightGear?

To fly an ILS approach in FlightGear, tune the destination runway’s localiser frequency in NAV1, select NAV or VLOC, set the published front course, intercept the localiser from below the glideslope, and follow both needles to decision altitude. Continue only with the required visual references; otherwise fly the missed approach.

The localiser supplies left-and-right guidance, while the glideslope supplies vertical guidance. Neither controls airspeed, landing configuration or the flare, so the pilot or the aircraft’s other systems must still manage those parts of the approach.

What information do I need before flying the ILS?

Before joining the approach, identify the exact runway end, frequency, course, intercept altitude, applicable minima and missed-approach procedure.

FlightGear’s airport information can help with basic planning, but use an instrument approach chart that matches the simulator’s navigation data where possible. Our guide to reading aviation charts in a flight simulator explains where to find the required figures.

• Approach and runway: Confirm that the procedure is for the runway end you intend to land on and that it is a full ILS rather than a localiser-only approach.
• Localiser frequency and identifier: Record both. The identifier provides an independent check that the receiver has selected the intended facility.
• Published front course: Use the charted value, not an estimate derived from the runway number.
• Intercept altitude: Note the altitude at which the glideslope should be intercepted and every preceding altitude restriction.
• Minimums: Select the decision altitude or height applicable to the aircraft and procedure, and set the local pressure correctly when using a barometric decision altitude.
• Missed approach: Brief the initial climb, altitude and turn before descending. This is the wrong time to start reading the procedure.

Does pista 12 mean the ILS course is 120 degrees?

Pista 12 means runway 12, but it does not guarantee that the published ILS course is exactly 120 degrees. A runway designation is based on its approximate magnetic direction, rounded to the nearest ten degrees with the final zero omitted.

The ILS for runway 12 may therefore have a charted front course a few degrees either side of 120. Its opposite end will normally be designated runway 30, but each direction has separate approach facilities and may use a different frequency—or have no ILS at all. Always tune the facility for the runway end being approached.

How do I fly the ILS in the FlightGear sim?

The reliable sequence is to prepare the radios early, intercept the localiser from the front, remain below the glideslope and make progressively smaller corrections as the runway gets closer.

1. Choose an ILS-capable aircraft. Confirm that the FlightGear aircraft has a working NAV receiver and a CDI, HSI or other display capable of showing both localiser and glideslope deviation. Avionics are implemented by each aircraft model, so two panels may not behave identically.
2. Brief and stabilise. Set the altimeter, calculate an appropriate approach speed, review the missed approach and arrange the aircraft so that tuning radios will not compete with basic control.
3. Tune and identify NAV1. Enter the localiser frequency and transfer it to the active side. The paired glideslope frequency is selected automatically; it is not tuned separately. Check the displayed or audible identifier if the aircraft model supports it.
4. Select NAV or VLOC. A mistake we see constantly is leaving the CDI or HSI connected to GPS. Change the source to radio navigation before intercept. Set the published inbound course on the HSI or course selector. On a basic CDI, the OBS setting may not alter raw localiser deflection, but the correct course still provides a useful reference and may be needed by the autopilot.
5. Intercept from the front and below. Approach at the published intercept altitude, normally with a localiser intercept angle of about 20–30 degrees. Avoid capturing from above: false glideslope lobes can exist above the proper path, and diving to recover usually produces an unstable approach.
6. Capture the localiser first. As the lateral needle comes alive, turn towards the inbound course. Use small heading changes and allow for a crosswind crab rather than trying to force the aircraft onto the runway heading. Localiser sensitivity increases towards the transmitter, so reduce the size of each correction.
7. Intercept the glideslope. When approaching from below, the glideslope needle starts above centre and moves down. Hold the published altitude until it reaches the centre, then establish the descent. If the needle is already below centre, the aircraft is above the path; do not dive after it.
8. Control the descent and speed. Configure the aircraft according to its checklist, maintain the target approach speed and follow the needles. For a typical three-degree path, groundspeed multiplied by five gives a useful initial descent rate: 90 knots is about 450 feet per minute. Treat that as a starting point, not a substitute for the glideslope indication.
9. Make the decision at minimums. At the published decision altitude or height, continue only if the required runway environment is visible and the aircraft can make a normal, stable landing. Otherwise apply go-around power, establish a positive climb, manage the configuration and fly the published missed approach.

Do I need GPS or ADF for a FlightGear ILS approach?

A conventional ILS does not require GPS or ADF, although either system may be used elsewhere in the published procedure.

GPS can guide the aircraft to an initial fix or towards the localiser intercept, but the final ILS guidance comes from the radio receiver. Panels with a GPS/NAV or GPS/VLOC selector must be switched to the radio source before capture; our FlightGear GPS and navigation-source guide explains that handover.

An ADF is needed only when the selected procedure uses an NDB for a feeder route, fix or missed approach. It is not part of the localiser or glideslope system itself.

Can the FlightGear autopilot fly the ILS?

A FlightGear autopilot can follow an ILS only when the chosen aircraft model supports coupled localiser and glideslope modes.

• Use heading and altitude modes to establish a stable intercept from below the glideslope.
• Confirm that NAV1 is active and the displayed source is NAV or VLOC, not GPS.
• Arm APR, APP or the aircraft-specific approach mode before reaching the localiser.
• Watch the mode annunciations. Verify that localiser and glideslope modes change from armed to captured; an illuminated approach button alone does not prove capture.
• Continue managing power, speed, flaps and landing gear unless the aircraft explicitly models systems that handle them.
• Disconnect or go around if the autopilot crosses the localiser, pitches aggressively, captures an unexpected signal or leaves the approach unstable.

Some simple FlightGear autopilots track only the localiser. Others couple both axes but use capture logic that differs from another aircraft, even when the panel buttons look similar.

Does ILS capture mean FlightGear can autoland?

No. Capturing LOC and GS does not by itself provide an automatic landing.

Autoland requires a suitably modelled aircraft, the correct configuration, supported autopilot modes and an appropriate runway facility. Unless the aircraft’s documentation explicitly describes a working autoland system, plan to disconnect and land manually.

Why will the localiser or glideslope not capture?

ILS capture failures usually result from the wrong navigation source, an inactive frequency, incorrect intercept geometry, the wrong runway end or incomplete avionics in the aircraft model.