GFC500 Update

[StevenL757]

On 11/11/2020 at 5:21 PM, donkaye said:

That's actually a good thing.  Switch off the G500/G500Txi and you still have your autopilot without Heading (unless you installed an extra GMU 11 with the G5).  I've tested it and it works perfectly.

Don, right now I have the MAG500 dedicated heading input to the ESI500.  Will the GMU11 provide that same dedicated functionality to the GI275?

[donkaye]

1 hour ago, StevenL757 said:

Don, right now I have the MAG500 dedicated heading input to the ESI500.  Will the GMU11 provide that same dedicated functionality to the GI275?

Yes.  When I had the ESI 500, which was a great backup,  I chose not to have the MAG500, but got heading from the G500 GMU 11.  I didn't want to always have the 2 headings not align by a few degrees.  In the unlikely event that the basic PFD fails, the reversion to TRK works just fine for the short amount of time necessary to get on the ground and have the main unit repaired.

[StevenL757]

Got it...thanks.

[vorlon1]

On 3/14/2020 at 5:37 AM, bradp said:

unless you’re coming from a BK autopilot there won’t be enough space on your yoke for the required trim switch and AP disconnect button. I wasn’t about to spend $500 for an out of stock plastic piece of unobtanium, so I fabricated a one-off that works perfectly.  If I had a 3D printer this would have been a great application.   
 

Can someone--perhaps @Bradp--speak to this? I'm struggling to find a requirement to locate these on the yoke.

Here is the problem: with a stock 67 C yoke it's impossible to do...

I have looked at the FAR's (and STC's as far as I can) to locate the requirement.

Don't get me wrong, I'm happy to be shown the regulation, but haven't found it yet.

[bradp]

32 minutes ago, vorlon1 said:

Can someone--perhaps @Bradp--speak to this? I'm struggling to find a requirement to locate these on the yoke.

Here is the problem: with a stock 67 C yoke it's impossible to do...

I have looked at the FAR's (and STC's as far as I can) to locate the requirement.

Don't get me wrong, I'm happy to be shown the regulation, but haven't found it yet.

I don’t think you’ll find it in the regs. But there is some language in the STC install manual that pretty much states where the AP disco and TOTO switches reside, then shops interpret that within reason.  I haven’t personally laid eyes on that STC install manual.  @Baker Avionics can probably give us some insight.  For practical purposes, @kpaul I think has a vintage style yoke so should be able to let us know how they did it with that particular setup. 

[bradp]

Just now, bradp said:

I don’t think you’ll find it in the regs. But there is some language in the STC install manual that pretty much states where the AP disco and TOTO switches reside, then shops interpret that within reason.  I haven’t personally laid eyes on that STC install manual.  @Baker Avionics can probably give us some insight.  For practical purposes, @kpaul I think has a vintage style yoke so should be able to let us know how they did it with that particular setup. 

Also you should be able to locate trim on the left horn along with ptt and disco on the right horn.  Unless the STC says something impractical. 

[201Mooniac]

Here is what the GFC-500 STC install manual has to say about switches:

 

3.4.5 Switches

The GFC 500 requires the installation of an autopilot disconnect switch on the pilot’s flight controls. If the GFC 500 installation includes manual electric trim, the installation of a trim switch on the pilot’s flight controls is also required. See Section 3.2 for switch part number.

The switch installation must meet the following criteria;

• Must be within easy reach of one or more fingers/thumb of the pilot’s left hand, when the hand is in a position for normal use on the pilot’s flight controls

• Must be easily located by the pilot without visual reference

• Must be located so that any action to operate switch will not cause an unintended input

  to the aircraft flight controls

• Must be located to minimize inadvertent operation and interference from other nearby

  switches or devices

• For aircraft without Pitch Trim installed, the Autopilot Disconnect switch must be labeled

  AP DISC.

• For aircraft with Pitch Trim installed, the Autopilot Disconnect switch must be labeled AP

  DISC/TRIM INT.

• The Trim Switch must be labeled TRIM and the directions must be labeled UP and DOWN (or DN).

• Switches must be clearly labeled as defined in Section 3.4.7
  The installation of these switches may require that the installer fabricate a bracket. If a bracket

  must be fabricated, the bracket installation must meet the following criteria;

• Must not interfere with the pilot’s hand when in a position for normal use on the pilot’s flight controls

• Must not obstruct the pilot’s view of any instrumentation or annunciations

• Must be rigid enough to prevent deformation under normal operation of the installed

  switches

• Must not interfere with other nearby switches or devices

• Must be fabricated from metal with no sharp edges

• The installation must be treated as if it were a structural repair and completed in

  accordance with AC 43.13-1B chapter 4, section 4.

  Installer is responsible for approval of any modification of the pilot’s flight controls and any needed brackets. Figure 3-1 shows the GFC 500 switches mounted in the left handle of a control wheel, this method is preferred when possible. Figure 3-2 shows examples of alternative methods for mounting the control wheel switches using a field fabricated bracket.

Installation of the GFC 500 Autopilot also requires a Go Around switch. See Section 3.2 for switch part number. The installation of the Go Around switch must meet the following criteria;

• Must be within easy reach of the hand that normally operates the throttle

• Must be easily located by the pilot without visual reference

• Must be located so that any action to operate switch will not cause an unintended input

  to the aircraft flight or engine controls

• Must be located to minimize inadvertent operation and interference from other nearby

  switches or devices

• Switch must be clearly labeled “GO AROUND” as defined in Section 3.4.77

[kpaul]

So I realized that I don't have a current photo of my yoke since the GFC install.  However, I have the "mongo" yokes that were only in the F in 75 & 76.  The new install is very similar. 

[pirate]

Not sure if your yokes are like mine but this is how I’d did my 70C yoke switches for my Stec-30. 
 

[vorlon1]

9 hours ago, pirate said:

Not sure if your yokes are like mine but this is how I’d did my 70C yoke switches for my Stec-30. 
 

 

I looked around for the installation doc and couldn't find it. Thanks.

My yoke is like yours. This is a good, and probably best, solution with two issues the way I see it.

1: The trim switch. It sounds like section 3.2 call out a specific 'rocker' type? It infers a specific part number. (is this included?) Would it be possible to mount it on a plate like this, or would two separate (one for up one for down) switches acceptable under section 3.2? 

2: Like many people, I put a tablet between the yoke horns like kpaul above.

Bottom line is it's a real bummer modern yokes are hard to find and $$$.  Looks like I might even have to consider getting a field approval.

Thanks all.

[bradp]

It’s this switch 

 

[pirate]

When I installed electric trim we made another bracket for the yoke (pictured) so the electric trim can be operated with left thumb like the auto pilot switches. 

Im also able to use a iPad mini on the yoke with no interference. 

Since these pictures I ran the wires up the yoke. 

I would think a bracket for your trim switches can be easily made. 
 

[jetdriven]

On 11/11/2020 at 5:21 PM, donkaye said:

That's actually a good thing.  Switch off the G500/G500Txi and you still have your autopilot without Heading (unless you installed an extra GMU 11 with the G5).  I've tested it and it works perfectly.

The gi275 has its own heading via GMU11 

[donkaye]

15 hours ago, jetdriven said:

The gi275 has its own heading via GMU11 

Same thing as the G5.  I chose not to install the GMU 11. because during normal flight operations there would be a difference between the GMU 11 of the G5 and the GMU 44 of the TXI.  For the rare time that the TXi failed track would be adequate to run an approach and get on the ground.

[jetdriven]

Yep.  Fwiw the 275 syncs heading to the TXi and it powers the gmu11 by itself through the battery pack. A nice addition but it’s expensive compared to the g5

[donkaye]

21 minutes ago, jetdriven said:

Yep.  Fwiw the 275 syncs heading to the TXi and it powers the gmu11 by itself through the battery pack. A nice addition but it’s expensive compared to the g5

Whoa there.  I must be missing something in the above.  Are you saying that you think the TXI with its GMU 44 and the GI 275 with its GMU 11 sync together at the same time?

[jetdriven]

1 hour ago, donkaye said:

Whoa there.  I must be missing something in the above.  Are you saying that you think the TXI with its GMU 44 and the GI 275 with its GMU 11 sync together at the same time?

Yes, we see this when the 500Txi boots up, it’s syncs  the 275 heading to the 500 heading. It does this through the HSDB ethernet connection. The 500 TXI has a GMU44, while the 275 has its own  internally powered gmu11. And they differ by 1° or even two. But as soon as this 500 TXI is online. Bang they synchronize. They  also synchronize is the altitude bug air speed bug heading bug altimeter sitting. Those things 

 

Edited February 1, 2021 by jetdriven

[donkaye]

2 hours ago, jetdriven said:

Yes, we see this when the 500Txi boots up, it’s syncs  the 275 heading to the 500 heading. It does this through the HSDB ethernet connection. The 500 TXI has a GMU44, while the 275 has its own  internally powered gmu11. And they differ by 1° or even two. But as soon as this 500 TXI is online. Bang they synchronize. They  also synchronize is the altitude bug air speed bug heading bug altimeter sitting. Those things 

 

Can you point me to the source?  I was not aware of this and, if true, wonder if the G5 does the same thing with a GMU 11.

[Marc_B]

I've been reading the threads regarding G5/GFC500 install and looking to replace ESI500 with the G5 vs GI275; currently use G500 as primary.  Seems like longer battery life of the g5 and cheaper pricing has the edge for backup.  But trying to reconcile GMU44 and need for GMU11.  I like the idea of having headings, altitudes, etc sync.

Will G5 (or GI275) backup sync with G500(TXI)?  Is there a reason to install G5 with GMU 11 in addition to the GMU44 I already have installed with the G500?  In G500 failure I'd still have GTN sending GPS info to backup.  Any compelling reason that swings GI275 above G5?

[PT20J]

You really have to check the STC installation manuals for details. Given some knowledge of Garmin's architecture, however, I would expect the GI 275 to integrate better with the G500 than the G5 which is really designed for CAN bus systems.

[donkaye]

11 hours ago, Marc_B said:

I've been reading the threads regarding G5/GFC500 install and looking to replace ESI500 with the G5 vs GI275; currently use G500 as primary.  Seems like longer battery life of the g5 and cheaper pricing has the edge for backup.  But trying to reconcile GMU44 and need for GMU11.  I like the idea of having headings, altitudes, etc sync.

Will G5 (or GI275) backup sync with G500(TXI)?  Is there a reason to install G5 with GMU 11 in addition to the GMU44 I already have installed with the G500?  In G500 failure I'd still have GTN sending GPS info to backup.  Any compelling reason that swings GI275 above G5?

The G500/G500TXi will sync Baro and Heading to the G5 without the addition of the GMU 11.  The downside is Heading is lost if the G500/G500TXi fails.  I don't find that much of an issue, since Heading reverts to Track in that situation.  I also like it better without the GMU11 because Heading on both are the same.  With the GMU 11, since Heading is coming from two sources, it can vary a couple of degrees between the two systems.  I'm not sure  about the GI275, but think  it is the same.

I personally like the G5.  The GI275 wasn't available when I did my  upgrade.  It is a little brighter, but the G5 is plenty bright.  The G5 AI displays navigation source in use and, when on the ground, displays DA automatically.  When interfaced to the GFC500 it does require the GAD 29B.

[PT20J]

6 hours ago, donkaye said:

The G500/G500TXi will sync Baro and Heading to the G5 without the addition of the GMU 11.  The downside is Heading is lost if the G500/G500TXi fails.  I don't find that much of an issue, since Heading reverts to Track in that situation.  I also like it better without the GMU11 because Heading on both are the same.  With the GMU 11, since Heading is coming from two sources, it can vary a couple of degrees between the two systems.  I'm not sure  about the GI275, but think  it is the same.

I personally like the G5.  The GI275 wasn't available when I did my  upgrade.  It is a little brighter, but the G5 is plenty bright.  The G5 AI displays navigation source in use and, when on the ground, displays DA automatically.  When interfaced to the GFC500 it does require the GAD 29B.

Don, is your GMU 44 on a separate breaker and if so have you tried failing it? As I understand it, the TRK lateral mode on the GFC 500 was originally for Experimental installations that didn't have a magnetometer. So, in the case of a failed GMU, I guess that the TRK mode would be the appropriate mode for the GFC, but Garmin's documentation isn't clear. What's your understanding?

Skip

[donkaye]

19 minutes ago, PT20J said:

Don, is your GMU 44 on a separate breaker and if so have you tried failing it? As I understand it, the TRK lateral mode on the GFC 500 was originally for Experimental installations that didn't have a magnetometer. So, in the case of a failed GMU, I guess that the TRK mode would be the appropriate mode for the GFC, but Garmin's documentation isn't clear. What's your understanding?

Skip

I'll have to check on the circuit breaker question.  I do know that I have turned off the G500TXi in visual conditions and successfully flew both an ILS and GPS approach to minimums with the G5 and GFC 500.