GFC500 Update

[gsxrpilot]

38 minutes ago, johncuyle said:

Dual or triple 7" G3X?  Two on the left, one on the right?  They added the ability to configure a screen as a copilot display, so assuming it all fits you could have attitude plus SV on one G3X, a moving map on the other, and the third one on the right configured as a copilot display, with two failovers.  If I had unlimited money, this is probably what I'd want.  Sadly...

Nevermind the money! I don't want all that cluttering up my panel. And are the G3X's legal backup's for each other? I didn't think they were.

[johncuyle]

On 2/5/2020 at 11:53 AM, gsxrpilot said:

Nevermind the money! I don't want all that cluttering up my panel. And are the G3X's legal backup's for each other? I didn't think they were.

Apparently not.  I'm not sure how two 7" portrait screens qualify as clutter.  The G500TXi can be configured consists of a pair (or trio) of portrait screens and that doesn't seem like clutter either.  An additional G5 or GI 275 doesn't seem so bad.  I don't think there's another solution that doesn't require some sort of backup.  The Dynon requires a D10, doesn't it?

[aviatoreb]

Question: how much does gfc500 go inop if it looses gps signal?

-entirely inop so it looses all function even the touted esp and also straight and level function - these are the primary safety features why I would consider upgrading from kfc200.  But if they were to go inop just when you might want them most - hand flying in Imc and annoyed...

-or maybe you just loose just the ability for a coupled approach but you can still use gfc500 manual mode features.  Such as fly heading and altitude hold or altitude descent while flying an approach but no longer as an lpv?

[adverseyaw]

I have a GFC 500 and fly in an area with lots of low overcast and a few military GPS interruptions every year. So I called pulled out my AFMS and called Garmin pilot support for clarification. TL; DR: the autopilot gives up when GPS is lost.

Here's the page of the AFMS for M20J and M20K:

 

 

Roll mode (ROL) maintains current bank. It is not a wing-leveler. Garmin pilot support confirmed this is the mode the 500 will enter on GPS loss when on GPS, VOR, localizer, and backcourse approaches.

Pitch mode (PIT) maintains current pitch. Although the AFMS says the 500 reverts to PIT on ILS tracking, Garmin pilot support clarified that both the ROL and PIT modes are applied.

When the autopilot mode switches due to GPS loss, the pilot can select a new mode, although Garmin pilot support says reselecting approach mode will kick it back into ROL or PIT.

 

My interpretation is that when GPS interruption occurs while on a radio approach, the GFC 500 gives up and keeps the aircraft in its current attitude.

 

Three things that are not clear to me (and which I plan to ask Garmin support if I have time this week):

1. This limitation only applies if a GPS navigator is installed. Is the 500 capable of working without a GPS nav head? If so, why does this limitation exist?
2. Which autopilot modes are usable during a GPS interruption?
3. What annunciations accompany GPS loss and reversion to ROL/PIT? I assume it's just the tiny icons on the G5 but want to clarify.

 

 

[Emmet]

According to the pilots guide if the ROL mode is activated as a result of a mode reversion it will bring the wings level and not maintain the current bank.

 

You should be able to fly the approach using HDG and PITCH mode if you still want AP support.

[aviatoreb]

7 minutes ago, Emmet said:

According to the pilots guide if the ROL mode is activated as a result of a mode reversion it will bring the wings level and not maintain the current bank.

 

You should be able to fly the approach using HDG and PITCH mode if you still want AP support.

That sounds like a reasonable and graceful failure mode of a loss of GPS signal.

[adverseyaw]

Very confusing. ROL mode is described independently of wings-level mode (see below). The Garmin tech confirmed that ROL mode would maintain bank.

What you're describing is intuitively what I would expect the autopilot to do, although the sources say otherwise. Do you have a page number for that? I'd like to take back to Garmin for clarification.

Edited February 9, 2020 by adverseyaw

[Emmet]

Here youngo

 

 

[Steve W]

11 hours ago, adverseyaw said:

Three things that are not clear to me (and which I plan to ask Garmin support if I have time this week):

1. This limitation only applies if a GPS navigator is installed. Is the 500 capable of working without a GPS nav head? If so, why does this limitation exist?
2. Which autopilot modes are usable during a GPS interruption?
3. What annunciations accompany GPS loss and reversion to ROL/PIT? I assume it's just the tiny icons on the G5 but want to clarify.

The G5 always has to have a source of GPS data, if you don't have a GPS Navigator it can use a signal from a WAAS transponder or a GPS receiver inside the G5.

Presumably the failure would be the same(if you had a compatible nav receiver and LOC/ILS/VOR) and you'd lose navigation tracking but could continue with heading/roll and vertical modes.

 

Edited February 10, 2020 by Steve W

[gsxrpilot]

13 hours ago, Hyett6420 said:

Do you happen to know whether the auto disengage for the 230 match the same as the kfc150, in terms of roll rate and pitch rate?   

I do not know that answer. I can reach out to my local BK guy and see if I can find that answer for you.

[gsxrpilot]

On 2/6/2020 at 4:33 PM, johncuyle said:

Apparently not.  I'm not sure how two 7" portrait screens qualify as clutter.  The G500TXi can be configured consists of a pair (or trio) of portrait screens and that doesn't seem like clutter either.  An additional G5 or GI 275 doesn't seem so bad.  I don't think there's another solution that doesn't require some sort of backup.  The Dynon requires a D10, doesn't it?

My comment was a little "tongue in cheek" but I don't like the requirement to have to screens, essentially the same, where the second is only there for backup.

There is another solution that doesn't require that sort of backup and it's Aspen. I have have an Aspen PFD and an Aspen MFD installed in my panel and no other back up required. If the PFD fails, the MFD becomes a PFD and provides the backup. In that case the MFD is gone, but it's not required anyway. Garmin has always required a backup for the PFD (AI) that isn't the MFD. To me, that's a waste of screens and real estate.

Of course, just my opinion and personal taste.

[donkaye]

1 hour ago, gsxrpilot said:

Garmin has always required a backup for the PFD (AI) that isn't the MFD. To me, that's a waste of screens and real estate.

 

The G500 TXi is one screen and the G5 is the other.  No wasted screens.

[gsxrpilot]

7 hours ago, donkaye said:

The G500 TXi is one screen and the G5 is the other.  No wasted screens.

I'm very hesitant to disagree with the Professor... 

During normal operations... what is the G5 displaying, that isn't also being displayed on the G500 TXi? Or what data is the G5 giving you that the G500 TXi isn't? I'm not the expert on that system, but I don't believe there is any reason, during normal operations, for the pilot to be looking at the G5. I understand that it's required by the GFC500 and it's required if the G500 TXi fails. But during normal operations, it's not providing anything the G500 TXi isn't already providing. 

To me that is a wasted screen. Again, just my opinion.

In the Aspen world I have one screen as the PFD (AI + HSI) and the other screen as the MFD. Both are useful during normal operations. In the event of a failure of the PFD, the MFD drops it's MFD functions, which are more "nice to have" than required, and becomes the PFD (AI + HSI). 

To me, this is a better use of panel real estate. Again, just a personal preference. 

[Emmet]

I would call that additional and not really wasted screen ... yes it displays the same information, but depending on the placement it reduces eye and head movements which can beneficial. And talking about redundancy you have two devices with different software which will not fail with the same software bug  ..

Looking at the dual Aspens in comparison to a G500txi or G3X you have additional bezels that waste space which cannot be used for display area.

You also cannot combine them to a single display area which limits the HMI capabilities ...

At the end it is all about preferences 

Just my 2 cents ..

[johncuyle]

On 2/9/2020 at 9:03 PM, gsxrpilot said:

My comment was a little "tongue in cheek" but I don't like the requirement to have to screens, essentially the same, where the second is only there for backup.

There is another solution that doesn't require that sort of backup and it's Aspen. I have have an Aspen PFD and an Aspen MFD installed in my panel and no other back up required. If the PFD fails, the MFD becomes a PFD and provides the backup. In that case the MFD is gone, but it's not required anyway. Garmin has always required a backup for the PFD (AI) that isn't the MFD. To me, that's a waste of screens and real estate.

Of course, just my opinion and personal taste.

Yeah, that makes sense.  Having looked pretty hard at the Aspens as a possible replacement for my gyros a couple times I decided I didn't really like the Aspen at all and would much prefer some sort of dual large screen and, because I'm paranoid, a couple of other backups don't seem so bad.  I do kinda agree that the G500TXi/GFC500 setup where the G500 drives the AP through the G5 kinda sucks.  Maybe I'd prefer something like a lifesaver with extra battery backup since it's not prone to some sort of weird software issue rendering it useless (or whatever)? 

I do understand the desire for failover to be as little a change in operations as possible, though.  If your G500 goes blank, flying on a G5 is a pretty big step down in available information (hope your engine monitor wasn't integrated into it either, if it was you now have big stress flying with no engine instruments and just a G5 with a different information display.) If you've got a two or three screen Aspen setup and one of them goes out, not that big a change. 

[donkaye]

48 minutes ago, johncuyle said:

Yeah, that makes sense.  Having looked pretty hard at the Aspens as a possible replacement for my gyros a couple times I decided I didn't really like the Aspen at all and would much prefer some sort of dual large screen and, because I'm paranoid, a couple of other backups don't seem so bad.  I do kinda agree that the G500TXi/GFC500 setup where the G500 drives the AP through the G5 kinda sucks.  Maybe I'd prefer something like a lifesaver with extra battery backup since it's not prone to some sort of weird software issue rendering it useless (or whatever)? 

I do understand the desire for failover to be as little a change in operations as possible, though.  If your G500 goes blank, flying on a G5 is a pretty big step down in available information (hope your engine monitor wasn't integrated into it either, if it was you now have big stress flying with no engine instruments and just a G5 with a different information display.) If you've got a two or three screen Aspen setup and one of them goes out, not that big a change. 

Actually the G5 drives the autopilot, period.  Data from the G5 syncs with the G500/G500TXi.  Except for a smaller screen the G5 provides all the important PFD information provided on the G500TXi.  In fact, when on the ground, the G5 provides density altitude when moving less than 30 knots.  This is not provided on the G500TXi.

[PT20J]

On 2/13/2020 at 12:02 PM, donkaye said:

Actually the G5 drives the autopilot, period.  Data from the G5 syncs with the G500/G500TXi.  Except for a smaller screen the G5 provides all the important PFD information provided on the G500TXi.  In fact, when on the ground, the G5 provides density altitude when moving less than 30 knots.  This is not provided on the G500TXi.

Hey, Don, a couple if questions:

Do all GFC 500 installations require the G5? I thought that the autopilot logic is distributed between the G5 and the servos with the mode controller just being a “dumb” user interface. 

The ROLL mode holding bank is interesting. In my experience, autopilots without a turn knob hold wings level in roll mode. Do you find this feature useful?

Thanks, 

Skip

[Baker Avionics]

2 hours ago, PT20J said:

Hey, Don, a couple if questions:

Do all GFC 500 installations require the G5? I thought that the autopilot logic is distributed between the G5 and the servos with the mode controller just being a “dumb” user interface. 

The ROLL mode holding bank is interesting. In my experience, autopilots without a turn knob hold wings level in roll mode. Do you find this feature useful?

Thanks, 

Skip

Skip, the GFC500 HAS to have a G5 per the STC and because of the CAN network that ties into it.  

[Emmet]

.. or the G3X Touch ..

[donkaye]

11 hours ago, PT20J said:

The ROLL mode holding bank is interesting. In my experience, autopilots without a turn knob hold wings level in roll mode. Do you find this feature useful?

Thanks, 

Skip

That's news to me.  The GFC 700 can hold a roll angle between I think 6° and 22°, but it has CWS.  The GFC 500 doesn't have CWS.  So, if it can hold a roll angle I'd sure like to know how.

[PT20J]

11 minutes ago, donkaye said:

That's news to me.  The GFC 700 can hold a roll angle between I think 6° and 22°, but it has CWS.  The GFC 500 doesn't have CWS.  So, if it can hold a roll angle I'd sure like to know how.

Section 3.3.4.1 in the G5 manual: Activating ROLL commands wings level if bank <6 deg ; Holds current bank angle if 6 to 20 deg; holds 20 deg if bank angle is >20 deg.

[donkaye]

52 minutes ago, PT20J said:

Section 3.3.4.1 in the G5 manual: Activating ROLL commands wings level if bank <6 deg ; Holds current bank angle if 6 to 20 deg; holds 20 deg if bank angle is >20 deg.

Thanks for pointing out the documentation.  Now I remember reading it, but forgot about it.  I guess that tells you how important I think it is.  I've been sitting here trying to figure out when it would be useful, but haven't come up with a good reason yet.  I will try it out when I get my airplane back from Annual, as a novelty.  Maybe I can come up with a reason after I try it.

[ArtVandelay]

Thanks for pointing out the documentation.  Now I remember reading it, but forgot about it.  I guess that tells you how important I think it is.  I've been sitting here trying to figure out when it would be useful, but haven't come up with a good reason yet.  I will try it out when I get my airplane back from Annual, as a novelty.  Maybe I can come up with a reason after I try it.

Search and rescue?

[Emmet]

4 hours ago, donkaye said:

Thanks for pointing out the documentation.  Now I remember reading it, but forgot about it.  I guess that tells you how important I think it is.  I've been sitting here trying to figure out when it would be useful, but haven't come up with a good reason yet.  I will try it out when I get my airplane back from Annual, as a novelty.  Maybe I can come up with a reason after I try it.

flying 360s without moving the heading bug all the time

[khedrei]

On a twin with a caged failed engine.