ILS landing using FMC

[moranaduk]

I prgrammed FMC correctly with route including a landing at EGKk ILS27L.

 

ATC via Vatsim gave me vectors on approach which I followed.

 

I then wanted to switch back on autopilot to land using FMC but everytime I pushed tge Nav button it turned completely off course.

 

Any ideas ?

[bdf369]

A bit difficult since you didn't say which airplane you're flying, but the FMC will not fly an ILS approach.

 

When you're following vectors you're using HDG mode. To intercept ILS you need to Arm either APP or LOC mode with the NAV1 radio tuned to the correct ILS frequency. If you have a NAV/GPS switch you need to move it to NAV.

 

The reason you "Arm" either LOC (or it might be called NAV) or APP is so the aircraft will continue to hold HDG until the ILS radio signal is captured. To Arm, just press the NAV or LOC button and you should see that you're still in HDG mode but there should be an annunciation somewhere that shows you're Armed to intercept the signal.

 

The ILS has 2 radio signals: The localizer (LOC) and the Glideslope (G/S). in APP mode you are trying to capture and follow both. It's possible that you're intercepting the localizer before the glideslope is detected. In that case the glideslope indicator will just sit flat horizontal in the middle of the display. Don't go to APP mode (ie use LOC or NAV mode instead) until the G/S comes "alive", that is it should jump up above the horizon line to show you are below G/S and will intercept from below. Once G/S is captured the aircraft should descend. Make sure to adjust speed and get into landing configuration following G/S capture.

 

Usually you'll also be in ALT HOLD mode until G/S capture. The ALT HOLD will switch off automatically.

It's good form to set the inbound course (CRS) to match the ILS approach course, that way if you're looking at your nav instruments you should see you're on course after capturing the localizer signal.

[moranaduk]

Hi. Fantastic. I did what you said and it worked like a dream. Basically I hadnt been entering ILS details in NAV page on Fmc. Flying Aerosoft Airbus. I did this religiously on Pmdg 737. Thsnks alot for your excellent advice.