Garmin G5 Installation, Shuffling the Deck

[TrueCourse]

I'm flying a Cherokee with the standard non-EFIS six pack that includes an electric T&B indicator that has bit the dust. If flown IFR, the T&B needs to be replaced. If its replaced with a pre-owned or new T&B, the problem is solved. But, with future avionics upgrades considered, then it's possible to do something a little different now. And this is where I need some clarification.

If the eventual goal is for a dual G5 EFIS configuration in the AI and DG/HSI positions but its too early in the budget for two G5s, my thinking is one G5 can be bought now and placed in the T&B position, leaving the existing AI and DG in place. (G5 STC says: "If the G5 is installed as the primary attitude indicator, the existing rate of turn indicator must be retained. If the G5 is installed as the rate of turn indicator, the existing primary attitude indicator must be retained").

Later, another G5 (with GMU 11) can be purchased to serve as a DG/HSI, then move the first G5 from the T&B position to the AI position and pick up an old T&B. On a related side note, I was told by Garmin support that a G5 purchased as an ADI can't be used later as an DG/HSI, even if sent to Garmin for any necessary reconfiguration. Is a Garmin G5 purchased as a DG/HSI the same unit with the exception of an external GMU 11? When I read "can be configured in attitude, DG/HI/HSI and turn coordinator positions", is that configuration occurring at the Garmin level, or at installation? They did say with experimental use it can be configured on the fly, so I'm led to believe its simple to do at the tech or pilot level. Haven't uncovered this info yet.

Also, would a G5 going into an older Cherokee need a different panel (i.e., a metal panel)? STC says "must be installed in an instrument plane constructed of aluminum with a minimum thickness of .040 inches." I'm not too familiar with what is behind the old Royalite overlay.

Thanks!

 

[murphey]

Also, would a G5 going into an older Cherokee need a different panel (i.e., a metal panel)? STC says "must be installed in an instrument plane constructed of aluminum with a minimum thickness of .040 inches." I'm not too familiar with what is behind the old Royalite overlay.

Thanks!

You can remove the plastic overlay - about 10-12 screws - and see what's underneath. I just installed a G5 in the cherokee to replace the AI, no problem at all. IIRC most of the Piper panels are a 0.050 inch. You may want to find a caliper and measure yourself after removing the overlay. By the way, depending on the age of the overlay, consider cleaning both back and front sides then spraying the back side with silver paint, if it needs it. Makes the light from the little GE53 bulbs diffuse around the instruments better.

 

[TommyG]

I am pretty sure you cannot have a G5 in both the TC and AI. You must keep one of the vacuum driven either AI or TC. Majority of people keep the TC so the vacuum system can be pulled all together.

 

[murphey]

I am pretty sure you cannot have a G5 in both the TC and AI. You must keep one of the vacuum driven either AI or TC. Majority of people keep the TC so the vacuum system can be pulled all together.

Most TC are electric. Removing the AI & DG means you can remove the entire vacuum system. The issue with the vacuum system is with older autopilots, that need the vacuum system.

 

[Jesse Saint]

The G5 HSI and the G5 PFD are identical, just different add-on components. A G5 PFD can be changed to an HSI by adding the GMU11 and GAD29(b). If you did this, though, you would need either another G5 or retain AI & TC.

 

[Clip4]

I am pretty sure you cannot have a G5 in both the TC and AI. You must keep one of the vacuum driven either AI or TC. Majority of people keep the TC so the vacuum system can be pulled all together.

An electronic representation for the inclinometer and rate of turn are represented on a dual G5 installation.

 

[Salty]

An electronic representation for the inclinometer and rate of turn are represented on a dual G5 installation.

But the STC says it cannot replace both if the aircraft is certified for IFR.

The installation of the G5 requires the retention of the mechanical airspeed indicator,
altimeter, and vertical speed indicator.
• For installations in aircraft approved for IFR operations:
• If the G5 is installed as the primary attitude indicator, the existing rate of turn
indicator must be retained.
• If the G5 is installed as the rate of turn indicator, the existing primary attitude
indicator must be retained.
• For installations in aircraft approved for VFR-only operations;
• The G5 can be installed as the attitude indicator and rate of turn indicator without
retention of either the existing attitude indicator or rate of turn indicator.

 

[TrueCourse]

You can remove the plastic overlay - about 10-12 screws - and see what's underneath. I just installed a G5 in the cherokee to replace the AI, no problem at all. IIRC most of the Piper panels are a 0.050 inch. You may want to find a caliper and measure yourself after removing the overlay. By the way, depending on the age of the overlay, consider cleaning both back and front sides then spraying the back side with silver paint, if it needs it. Makes the light from the little GE53 bulbs diffuse around the instruments better.

Thanks, good info. So you simply trimed the overlay to make room around the G5? If I may ask, how much labor was involved in your one G5 AI installation?

The G5 HSI and the G5 PFD are identical, just different add-on components. A G5 PFD can be changed to an HSI by adding the GMU11 and GAD29(b). If you did this, though, you would need either another G5 or retain AI & TC.

Thanks, for confirming what I suspected.

 

[bnt83]

I would not pursue the two mx events approach like you are proposing, just replace the t&b now and do both G5s at once at a later date. Unless the labor is FREE you are going to be doubling up on a labor to do two events. You should be able to get a lot more solid installation by doing it all at once at a cheaper total invested cost.

I have installed 5 of them.

 

[Fracpilot]

I would not pursue the two mx events approach like you are proposing, just replace the t&b now and do both G5s at once at a later date. Unless the labor is FREE you are going to be doubling up on a labor to do two events. You should be able to get a lot more solid installation by doing it all at once at a cheaper total invested cost.

I have installed 5 of them.

This.

There’s a lot of labor taking the panel apart and putting it back together. You’re best to bite the bullet now instead of paying twice the labor costs (usually $100/hr) and just pay the labor once.

If you have the dual G5, the existing TC isn’t required anymore. Should the AI G5 fail, the G5 HSI becomes the backup and switches to the AI automatically. The G5 AI has a TC in it already. The AI G5 also has a compass with a dual G5 install so you would have everything you need as a backup with dual G5’s which allows you to rid of the the vacuum driven instruments and the TC.

Like someone said, if you have a vacuum driven autopilot, then the vacuum AI has to stay to drive that. I just went through all of this with my upgrade. I went ahead and put the dual G5’s in it. Couldn’t be happier.


Sent from my iPhone using Tapatalk

 

[chemgeek]

I would not pursue the two mx events approach like you are proposing, just replace the t&b now and do both G5s at once at a later date. Unless the labor is FREE you are going to be doubling up on a labor to do two events. You should be able to get a lot more solid installation by doing it all at once at a cheaper total invested cost.

I have installed 5 of them.

^^^^Yes! Expect up to 25-30 hours or labor to do a dual G5 install, including siting of the GMU-11 and configuring the GAD29B to work with your AP. If you do this in stages is will just cost more labor, which is already around the cost of one G5.

 

[TrueCourse]

I would not pursue the two mx events approach like you are proposing, just replace the t&b now and do both G5s at once at a later date. Unless the labor is FREE you are going to be doubling up on a labor to do two events. You should be able to get a lot more solid installation by doing it all at once at a cheaper total invested cost.

I have installed 5 of them.

I agree this is the best way to do it. I'm still learning about the number of install hours involved (haven't started any quotes yet), so my two step process only guessed at that part. Now the hours actually involved are coming in and I see the bigger picture. Thank you!

 

[Jesse Saint]

Dual G5’s with the GAD and installation should cost around $7,500. That’s what we charge. The T&B would be independent.

 

[TrueCourse]

This.

If you have the dual G5, the existing TC isn’t required anymore. Should the AI G5 fail, the G5 HSI becomes the backup and switches to the AI automatically. The G5 AI has a TC in it already. The AI G5 also has a compass with a dual G5 install so you would have everything you need as a backup with dual G5’s which allows you to rid of the the vacuum driven instruments and the TC.

Like someone said, if you have a vacuum driven autopilot, then the vacuum AI has to stay to drive that. I just went through all of this with my upgrade. I went ahead and put the dual G5’s in it. Couldn’t be happier.

Thanks. I see the logic behind "if you have the dual G5, the existing TC isn't required anymore" based on their capability, but in the STC there are only a few scenarios that are written about discarding the TC altogether (replacing it with an autopilot-used AI, etc.). The Installation Limitations seem to discuss single G5 installations in different positions, but nothing specifically different when using a dual installation for AI and DG/HSI. Where does it show that an AI + DG/HSI installation changes things? Is there more information that Garmin has published? Every last picture of a dual installation I've found still shows a TC (or AI).

 

[bnt83]

Thanks. I see the logic behind "if you have the dual G5, the existing TC isn't required anymore" based on their capability, but in the STC there are only a few scenarios that are written about discarding the TC altogether (replacing it with an autopilot-used AI, etc.). The Installation Limitations seem to discuss single G5 installations in different positions, but nothing specifically different when using a dual installation for AI and DG/HSI. Where does it show that an AI + DG/HSI installation changes things? Is there more information that Garmin has published? Every last picture of a dual installation I've found still shows a TC (or AI).

You are reading the manual correctly, the dual G5 system you ultimately want to end up with cannot replace an attitude gyro, direction gyro, and T/C or T/B at the same time.

The STC limitations are clear in the manual, forum posts can be wrong.

Now you may be able to REPLACE (not remove) the T/B or T/C with a different gyro such as another attitude gyro using data/approval other than the Garmin STC. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC91-75.pdf

 

[Jmcmanna]

From a practical standpoint, the way to go seems to be to replace the AI/DG with G5’s and leave the TC alone. You can ditch the vacuum system and your scan will be familiar.

The exception is that if you have an autopilot that needs the vacuum AI, you can move it to the TC spot.

Or, if you have room, you can keep them both!

https://m.imgur.com/gallery/SdfpUpj

 

[TrueCourse]

I noticed some other G5 related threads and know a lot of G5 installation questions have been asked over the past few years, including this one to some degree. Thanks for the feedback!

 

[chemgeek]

Bear in mind if your TC is driving the autopilot, e.g. STEC systems, you will keep the TC even with dual G5s to retain AP function. The TC/AP may require modification/update to work with the G5s.

In addition, if you go dual G5s you may be able to remove your vac system, which is more labor. That's what I did, as the vac system wasn't needed for anything else. Good riddance, I say. The dry pumps will fail at the most inopportune times. Sometimes they will go 500 hours, sometimes they die early for unknown reasons.