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Garmin autopilot and radio navigation aids

Dugaru

Well Known Member
Am I correct that my Garmin autopilot setup (G5, GMC307, two GSA28s) will display a localizer, VOR, and ILS glideslope (with the green diamonds), but will not "couple" to those nav sources?

Put another way, is my collection of Garmin autopilot gear capable of using only GPS as a NAV source?

If so, is this true of other GSA28 installations?

I'm embarrassed to say that I've never really given this capability much thought, since my usual mission is generally gentleman's IFR at worst, and involves few approaches (and those are GPS). And when practicing approaches (ILS, localizer, GPS, whatever) I usually hand fly.

But I'm headed out on a trip next month and was just wondering what the capabilities are if I need to do a non-GPS approach.
 
Do you have a radio capable of receiving VOR/LOC/GS connected to your system thru a GAD 29 A429 interface (you don't need the GAD 29 with a GNC 255/SL-30 or a radio that outputs the NAV signals via RS232 with the appropriate protocol(Val Nav Radios)) ? If not, you can’t display VOR/LOC/GS nor will you be able to couple to it.
 
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Yes, I have a 430W

Yes, I can get the VOR/LOC/GS from the 430W displayed on the G5 with no apparent problems. When I do so, that gives me little green CDI diamonds instead of the pink diamonds for the GPS.

But from what I can tell from the G5 manual, the only approach and glideslope options for the autopilot are with GPS as the NAV source.

Let me be the first to admit that I am no expert and it's possible I'm being boneheaded about this. :)

Do you have a radio capable of receiving VOR/LOC/GS connected to your system thru a GAD 29 A429 interface (you don't need the GAD 29 with a GNC 255) ? If not, you can?t display VOR/LOC/GS nor will you be able to couple to it.
 
Yes, I can get the VOR/LOC/GS from the 430W displayed on the G5 with no apparent problems. When I do so, that gives me little green CDI diamonds instead of the pink diamonds for the GPS.

But from what I can tell from the G5 manual, the only approach and glideslope options for the autopilot are with GPS as the NAV source.

Let me be the first to admit that I am no expert and it's possible I'm being boneheaded about this. :)

The certified product manual seems to have newer modes listed vs the experimental manual which seems to be behind the certified manual.....

I would contact TeamX at Garmin to be sure.

Have you tried coupling to a VOR/LOC/GS while you had the green indicators instead of the magenta ones?
 
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Do you have a radio capable of receiving VOR/LOC/GS connected to your system thru a GAD 29 A429 interface (you don't need the GAD 29 with a GNC 255) ? If not, you can?t display VOR/LOC/GS nor will you be able to couple to it.

Not entirely true. My Val NAV is wired through 232 and couples fine for NAV and GS. No GAD 29 required as it isn?t speaking ARINC.
 
My understanding is that the G5 will only take nav data via it's one RS-232 port or from the GAD airinc module connected via CAN. Not sure what it's ap couples to.

Larry
 
Hello,

The G5 installation manual shows several examples of single and dual navigators used in G5 based systems. Several examples include NAV radios that provide VOR/ILS navigation.

As long as your G5 software is up to date, you may couple the autopilot to the VOR/ILS green needles in any installation that provides them.

Thanks,
Steve

HS5_n0yXwOIYY8Ng0IJtqdEqf6Zf043ETtCCsgSnxpynzOt30YSmrrImieCi_R1qicldlD4HosfsmkDQAsPicv51AlNtPc841LnnZ1Dx1QR89_JaNist7hz1G6UJPx3Lgb8JFN6PHYTCTAqECAvuEH_vvgxj8H3XP6jF7hm8MpvXnbr9X4VzLtfa0ifkTGi0uALwQhFuQIb56VqZLze4QnOd4LGGbXvXnZ161Ys7JsEJt33eQxvst_sC4DHhUlKCohD9dUnhWLymQG_GAvvr-NlgsDjGCjUNmBVEJi4OOXznu9vRb1HQZ3toodcd09SEcgGGxP4933AlaCSHUsQQH41OzsHIaUAKwMOc_YI4jWMyj462FB66mZGxJwzO4-zfbpzwGrALUvt2SvTkf0RAUxz8YMiOwY7jog46YAVeCEj_0ObD56Mx-cGinzJzbR5moYVANb9M9mfnWzYeihcA3urybqQxAltEuhe1rlmDMCkO-orCn4LQpjUDmCkUPpZKIGd0hUoNfrE7Fm3CqifmpuQ4gzpoGA1sc1I1Q_9g47MfnB6jegxLyFqMBaIGv2_sGOEy37IDpEEPLYe9mEqYAqKc43dduShw7jxTWBleHJVYYOE-ijdvqeqnNXSUDxztD_n68mGFOvxrgNj16Xt3wTLQ=w441-h869-no
 
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Not entirely true. My Val NAV is wired through 232 and couples fine for NAV and GS. No GAD 29 required as it isn’t speaking ARINC.

Good point. Nav radio's that speak the appropriate protocol via RS232 (likely the old SL30 protocol) may work as well without the GAD 29.
 
coupling to VOR/ILS

Thanks -- so my G5/307/430W should be able to do this?

Hello,

The G5 installation manual shows several examples of single and dual navigators used in G5 based systems. Several examples include NAV radios that provide VOR/ILS navigation.

You may couple the autopilot to the VOR/ILS green needles in any installation that provides them.

Thanks,
Steve

HS5_n0yXwOIYY8Ng0IJtqdEqf6Zf043ETtCCsgSnxpynzOt30YSmrrImieCi_R1qicldlD4HosfsmkDQAsPicv51AlNtPc841LnnZ1Dx1QR89_JaNist7hz1G6UJPx3Lgb8JFN6PHYTCTAqECAvuEH_vvgxj8H3XP6jF7hm8MpvXnbr9X4VzLtfa0ifkTGi0uALwQhFuQIb56VqZLze4QnOd4LGGbXvXnZ161Ys7JsEJt33eQxvst_sC4DHhUlKCohD9dUnhWLymQG_GAvvr-NlgsDjGCjUNmBVEJi4OOXznu9vRb1HQZ3toodcd09SEcgGGxP4933AlaCSHUsQQH41OzsHIaUAKwMOc_YI4jWMyj462FB66mZGxJwzO4-zfbpzwGrALUvt2SvTkf0RAUxz8YMiOwY7jog46YAVeCEj_0ObD56Mx-cGinzJzbR5moYVANb9M9mfnWzYeihcA3urybqQxAltEuhe1rlmDMCkO-orCn4LQpjUDmCkUPpZKIGd0hUoNfrE7Fm3CqifmpuQ4gzpoGA1sc1I1Q_9g47MfnB6jegxLyFqMBaIGv2_sGOEy37IDpEEPLYe9mEqYAqKc43dduShw7jxTWBleHJVYYOE-ijdvqeqnNXSUDxztD_n68mGFOvxrgNj16Xt3wTLQ=w441-h869-no
 
Excellent

Many thanks. I'm definitely getting the green diamonds. So now comes the hard part: figuring out what I'm doing wrong! :)

I was thrown off by pages 169 and 172 of the G5 Install Manual and Pilot Guide (190-02072-00 Rev. C) which seems to say that the NAV and APR modes are GPS modes. For example, the asterisked note on the APR and NAV buttons, on page 172, says "The selected navigation receiver must have an active GPS course before NAV or APR Key press activates flight director" (emphasis added). I take it that it only really needs to be receiving data from the 430W?

Yes if you have a GAD 29 properly installed and configured. If you get the green needles, then you should be golden.
 
Many thanks. I'm definitely getting the green diamonds. So now comes the hard part: figuring out what I'm doing wrong! :)

I was thrown off by pages 169 and 172 of the G5 Install Manual and Pilot Guide (190-02072-00 Rev. C) which seems to say that the NAV and APR modes are GPS modes. For example, the asterisked note on the APR and NAV buttons, on page 172, says "The selected navigation receiver must have an active GPS course before NAV or APR Key press activates flight director" (emphasis added). I take it that it only really needs to be receiving data from the 430W?

Originally the G5 based AP system did not have VOR/LOC/GS abilities but now it does. Things change and manuals get outdated quickly. Best to use the latest manuals. The latest install manual for the experimental version is rev. 4. The latest Pilot guide for the experimental version is Rev. G. Lots have changed since rev C of that manual.
 
I need to RTLFM (read the LATEST freaking manual)

Ah. This is all becoming clear to me now. I really appreciate the info.

Originally the G5 based AP system did not have VOR/LOC/GS abilities but now it does. Things change and manuals get outdated quickly. Best to use the latest manuals. The latest install manual for the experimental version is rev. 4. The latest Pilot guide for the experimental version is Rev. G. Lots have changed since rev C of that manual.
 
Okay so I remain clueless

So:

- I've got the latest software installed, and the latest pilot guide for the G5.

- My gear is a G5, a 307, and a 430W.

- I can set up and fly a coupled GPS approach, including an LPV with vertical guidance, with no problem.

- I'm getting green navigational info displayed on the G5 when the 430W is switched to that.

Can somebody step me through how I would fly a coupled ILS, once that is set up in the 430W (and the 430W's CDI button is pressed as needed to send that nav data to the G5)?

I can't find this procedure in the pilot's guide, which (like the old one) still seems to indicate that NAV and APR modes are GPS only (see for example p. 48). By the same token, Glidepath Mode also appears to be GPS only (p. 61).

Basically, I think my problem is that I can't find a GlideSLOPE mode, or a lateral NAV mode that will track a VOR, localizer, etc.

But given the Garmin post above, I presumably am missing something obvious. :)

Thanks!
 
So:

- I've got the latest software installed, and the latest pilot guide for the G5.

- My gear is a G5, a 307, and a 430W.

- I can set up and fly a coupled GPS approach, including an LPV with vertical guidance, with no problem.

- I'm getting green navigational info displayed on the G5 when the 430W is switched to that.

Can somebody step me through how I would fly a coupled ILS, once that is set up in the 430W (and the 430W's CDI button is pressed as needed to send that nav data to the G5)?

I can't find this procedure in the pilot's guide, which (like the old one) still seems to indicate that NAV and APR modes are GPS only (see for example p. 48). By the same token, Glidepath Mode also appears to be GPS only (p. 61).

Basically, I think my problem is that I can't find a GlideSLOPE mode, or a lateral NAV mode that will track a VOR, localizer, etc.

But given the Garmin post above, I presumably am missing something obvious. :)

Thanks!

Just like when flying an LPV approach where you didn't have to find a GP mode to couple to the glidepath, you don't have to find a GS mode to fly a coupled ILS and couple to the glideslope.

You just press the APR button on your GMC 307 after tuning/activating the ILS approach, similar to what you did with the LPV approach.

NAV mode will track a LOC/VOR course just like NAV mode tracks a GPS course.

eJE049jaBu8_RuTFOcg9QxgpjyuFXnMPr72IIkcvJQA=w536-h184-no


When you fly an ILS approach, you will normally activate a heading vectors transition. As you approach the final approach course, the autopilot will be in HDG mode (receiving ATC vectors) laterally and ALT hold mode vertically. When you press the single APR button when an ILS approach has been activated on the navigator and you are using green needles, the flight director/autopilot automatically arms LOC mode laterally and GS mode vertically. You have pushed your last button until the autopilot captures the LOC signal and turns inbound and then captures the GS signal to descend to the runway. It is a good idea to press the APR button fairly soon after you activate the approach to make sure that you don't forget.

If you don't press the APR button and arm for the LOC/GS capture before you reach the inbound course, the aircraft will fly through the final approach course in HDG mode. I add this because this is one of our most often received questions. People get fixated watching the green needle center in the HSI, and forget to push the APR button to arm for capture and the automatic transition from HDG/ALT to LOC/GS.

One of the many reasons why many of us never want to fly another ILS approach is that when you fly LPV approaches with one of the published transitions, you never leave GPS mode. When flying an LPV, you can often reach target altitude and push the last autopilot button (APR) 20 nm or more outside the IAF and everything else is done by the autopilot until you reach the runway threshold. With LPV approaches being available at many more airports than ILS, it is now more important to be proficient at LPV approaches than ILS, but they are both super easy to fly with this autopilot (or hand fly with the flight director).

We are updating the non-certified manual. This manual is more up-to-date and section 3.3.7 on page 55 explains how to use the autopilot to fly an ILS approach.

Thanks,
Steve
 
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Got it

This was an extremely helpful explanation -- and I can't wait to try it out. Many thanks for the prompt and detailed response.

Agree completely about GPS approaches being preferable to ILSs, for all the reasons you mention. But I've found that busy controllers at large airports tend to assign ILSs as a matter of course (maybe airliners like them better?) and sometimes it's easier to just brief and fly the ILS than to use airtime requesting a GPS approach to the same runway.

Incidentally, it had not occurred to me that you could hit the APR button on an activated GPS approach that early. I had been pressing APR only once I was inbound on the final approach course (and yes, I once forgot to do it, for exactly the reason you mention.....). But if I'm reading you right: you can press APR on an LPV or LNAV+V approach as soon as you get to the altitude at which the glidepath (or I guess the advisory glidepath in the case of the LNAV+V) will eventually be captured?

Just like when flying an LPV approach where you didn't have to find a GP mode to couple to the glidepath, you don't have to find a GS mode to fly a coupled ILS and couple to the glideslope.

You just press the APR button on your GMC 307 after tuning/activating the ILS approach, similar to what you did with the LPV approach.

NAV mode will track a LOC/VOR course just like NAV mode tracks a GPS course.

eJE049jaBu8_RuTFOcg9QxgpjyuFXnMPr72IIkcvJQA=w536-h184-no


When you fly an ILS approach, you will normally activate a heading vectors transition. As you approach the final approach course, the autopilot will be in HDG mode (receiving ATC vectors) laterally and ALT hold mode vertically. When you press the single APR button when an ILS approach has been activated on the navigator and you are using green needles, the flight director/autopilot automatically arms LOC mode laterally and GS mode vertically. You have pushed your last button until the autopilot captures the LOC signal and turns inbound and then captures the GS signal to descend to the runway. It is a good idea to press the APR button fairly soon after you activate the approach to make sure that you don't forget.

If you don't press the APR button and arm for the LOC/GS capture before you reach the inbound course, the aircraft will fly through the final approach course in HDG mode. I add this because this is one of our most often received questions. People get fixated watching the green needle center in the HSI, and forget to push the APR button to arm for capture and the automatic transition from HDG/ALT to LOC/GS.

One of the many reasons why many of us never want to fly another ILS approach is that when you fly LPV approaches with one of the published transitions, you never leave GPS mode. When flying an LPV, you can often reach target altitude and push the last autopilot button (APR) 20 nm or more outside the IAF and everything else is done by the autopilot until you reach the runway threshold. With LPV approaches being available at many more airports than ILS, it is now more important to be proficient at LPV approaches than ILS, but they are both super easy to fly with this autopilot (or hand fly with the flight director).

We are updating the non-certified manual. This manual is more up-to-date and section 3.3.7 on page 55 explains how to use the autopilot to fly an ILS approach.

Thanks,
Steve
 
When you fly an ILS approach, you will normally activate a heading vectors transition. As you approach the final approach course, the autopilot will be in HDG mode (receiving ATC vectors) laterally and ALT hold mode vertically. When you press the single APR button when an ILS approach has been activated on the navigator and you are using green needles, the flight director/autopilot automatically arms LOC mode laterally and GS mode vertically.

A quick follow up to this. Does the approach need to be loaded and activated in the 430 or is it ok just to have the loc frequency tuned and in VLOC mode? This is how I have been flying it on the GRT, but moving to G3X on the new 10.

Larry
 
To fly an ILS with a 430/650, etc. it is never required to load the ILS from the database. For an ILS, all you need is 1) a valid localizer frequency in the active position and 2) be in VLOC mode on the navigator and HSI/CDI (green needles and green VLOC annunciation). That's all.

When you load a legacy/ground based IAP (VOR/LOC/ILS) in the navigator, you are basically calling up a GPS overlay of that IAP. The course guidance displayed on your nav indicator (HSI or CDI) is dependent on which selection (GPS or VLOC) is made on the navigator and HSI/CDI. It's that course guidance selection that either you or the autopilot follow.

The key to remember is that the nav function (green VLOC annunciation and appropriate frequencies) of the navigator (GNS-XXX or GTN-XXX) and the GPS function (database dependent, magenta GPS annunciation and needles, moving map display/line) are completely independent functions, but CAN be used as a team, if desired (and normally are).

Hope this helps.

George
 
Agree with George.

You give up a lot by not having the situational awareness of the approach overlaid on the moving map, and also won't have the GPS coupled missed approach ready to go if you press the TO/GA button at minimums - but your choice, Larry.

Thanks,
Steve
 
Incidentally, it had not occurred to me that you could hit the APR button on an activated GPS approach that early. I had been pressing APR only once I was inbound on the final approach course (and yes, I once forgot to do it, for exactly the reason you mention.....). But if I'm reading you right: you can press APR on an LPV or LNAV+V approach as soon as you get to the altitude at which the glidepath (or I guess the advisory glidepath in the case of the LNAV+V) will eventually be captured?

Hello Doug,

It is actually much simpler than that. As soon as you are cleared for the approach, you can activate the approach, (which makes the IAF the active waypoint) and then immediately press the APR button. The GPS lateral mode immediately captures, locking in GPS lateral navigation for the rest of the approach.

At this point, since you pressed the APR button, the white GP annunciation is parked up in the upper right of the autopilot mode bar as a reminder that GP capture is armed and ready when needed.

In the meantime, use selected altitude and whatever vertical mode such as VS, IAS, or PIT to climb or descend to the approach entry altitude. At times a white ALTS (selected altitude) indication will join GP as an armed vertical mode as you change altitude until that altitude is captured and GP is all that remains as an armed vertical mode.

Once you capture the proper altitude to begin the approach, you are done. The GP mode is still armed and ready to capture the glidepath near the FAF.

There is only one caveat to this which doesn't apply to your 430W. If you plan to use GTN VNAV for step downs in an LPV approach (rare), you will need to push the APR button and re-arm GP after those coupled step downs are complete. You can't presently have GP armed and use VNAV at the same time.

Thanks,
Steve
 
Very good posts and I confirm the g5 works fine for AP-coupled ils (in Europe we still use ils most of the time). I have however a more specific question: in my previous Garmin setup (g1000+gfc700) the autopilot (in "apr" mode) was chasing the ils course more aggressively than when chasing a cruise course in "nav" mode, which was also specified in the manual as the correct behaviour. Also, I believe to remember the HSI deviation-scale automatically changed to a finer scale during approach.

However, with my current setup (g3x/g5+gtn+gmc307) I have the impression that the AP doesn't chase more aggressively the localizer course when in "apr" mode compared to the way it chases a vor course in "nav" mode during cruise, with the consequence that when I disconnect the AP at the minima, the plane is often quite off-track from the runway centerline (especially with lateral wind). My Gain and Torque settings for the gmc307 autopilot are in line with other rv7 posting on VansAirforce and they work well in cruise. Does anybody know if the gmc307 automatically increases Gain and/or Torque while the "apr" button is pushed (like I imagine was the case for the gfc700)?
 
Very good posts and I confirm the g5 works fine for AP-coupled ils (in Europe we still use ils most of the time). I have however a more specific question: in my previous Garmin setup (g1000+gfc700) the autopilot (in "apr" mode) was chasing the ils course more aggressively than when chasing a cruise course in "nav" mode, which was also specified in the manual as the correct behaviour. Also, I believe to remember the HSI deviation-scale automatically changed to a finer scale during approach.

However, with my current setup (g3x/g5+gtn+gmc307) I have the impression that the AP doesn't chase more aggressively the localizer course when in "apr" mode compared to the way it chases a vor course in "nav" mode during cruise, with the consequence that when I disconnect the AP at the minima, the plane is often quite off-track from the runway centerline (especially with lateral wind). My Gain and Torque settings for the gmc307 autopilot are in line with other rv7 posting on VansAirforce and they work well in cruise. Does anybody know if the gmc307 automatically increases Gain and/or Torque while the "apr" button is pushed (like I imagine was the case for the gfc700)?

Due to the nature of how an ILS works (both GS and LOC get more sensitive the closer you are to the transmitters), it is automatically that way.

As far as I know there is no automatic increase in the set gains when in APR mode with the G3X system.

Sounds like you need to tweak your roll servo settings. You will need to find a happy place where the setting works well for both enroute and approach modes.

My airplane puts me right on the centerline all the time but I tweaked my gains until I was happy. All airplanes are slightly different so one set of settings do not fit all RV-7's out there.

The HSI deviation-scale is fixed on a LOC based approach. Deviation-scale only comes into play on GPS based approaches and the IFR Navigator should be taking care of that automatically.

One other thought..... when you experience this issue, what does the HSI deviation indicator display? Is it centered or is it offset? If it is centered and the airplane is not, then you have some issue with your LOC radio. Also if your antenna is in your wingtip, you will be off by half your wingspan.
 
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