ILS and Glide Slope Tracking

I Loaded an ILS approach to my flight plan and after being vectored to final the autopilot never locked on. Do you need to go back into the proc page to activate the approach or will it do it automatically.

What is the best way to (sequence of buttons) to ensure tracking ILS after being vectored to final?

Bob

What is the best way to (sequence of buttons) to ensure tracking ILS after being vectored to final?

From the STEC PIM:

If approach vectoring locates the aircraft above or too near the glideslope centerline at the intercept point, usually the outer marker, it becomes necessary to execute manual arming of the glideslope. This is done by: (a) pressing the ALT switch once if operating in the altitude hold mode, and (b) pressing the ALT switch twice if operating in the VS mode. Once capture is achieved, the GS annunciation will illuminate, and the ALT annunciation will extinguish.

Bob -

If you literally LOADED, but did not ACTIVATE, the ILS in the Garmin 430, you need to

  • LOAD the ILS approach (from an IAF or VTF)
  • ACTIVATE the approach (VTF if it was loaded with an IAF)
  • Swap the ILS freq from standby to active
  • Set the autopilot HDG bug to fly the intercept course
  • With the STEC55X, push HDG and NAV simulateously to fly lthe HDG to interecept the ILS
  • Once you’ve intercepted and are established, the autopilot should pick up and track the GS. If it doesn’t, pushing ALT twice (I think) will force the AP to track the GS as well.

Hope that helps.

Art,

I think the question was:

In reply to:


Do you need to go back into the proc page to activate the approach or will it do it automatically.


It’s been my experience that you need to activate the approach, making sure that you toggle the CDI from GPS to VLOC. Press HDG and NAV together, with ALT selected, and use the HDG bug to guide the airplane to the final approach course. When you get close enough to the final approach course, hdg will extinguish, nav will stay lit, alt will stay lit and approach will illuminate. You will now be tracking the final approach course. As long as you are far enough below the glideslope, and far enough from the FAF, you will also capture the glideslope. When that happens, alt will extinguish, VS will illuminate and GS will illuminate. Reduce RPM, one notch of flaps, and GUMP at the FAF, then enjoy the ride down.
Watch your DH, because the AP will fly you into the ground. That’s it. It’s an awesome combination of equipment.

In reply to:


…activate the approach, making sure that you toggle the CDI from GPS to VLOC…


Paul,

My Garmin switches from GPS to VLOC on its own; agree with the rest of your comments.

Also, my startup/taxi checklist includes a check NAV HEADS TO GPS, because that’s usually what I want, and if my last landing was after an ILS or LOC approach, the GNS430 will still be set to VLOC.

Mike.

In reply to:


My Garmin switches from GPS to VLOC on its own


True statement Mike. However, if you attempt to intercept the final approach course less than 2 nm from the FAF, the transition to VLOC should not happen. Also, if you’ve set this feature (ILS CDI) to “manual” mode, then it won’t switch either. This auto CDI switch is only valid for an ILS (localizer) and the switch won’t happen for a VOR approach.

In reply to:


Also, if you’ve set this feature (ILS CDI) to “manual” mode, then it won’t switch either.


Scott,

Thanks! You’re today’s contribution to the rule that has (so far) held for me: I learn something new every day on these forums.

Mike.

In reply to:


I learn something new every day on these forums.


Glad to help. Could not agree more! I’ve learned the hard way. Got bit by this one a couple of times until I finally figured out what was going on.