GI275 as G1000 Standby Instrument?

[Jeff_S]

I started a new thread here because it's specific to the newer Mooney's that have G1000 but still have the old electric-gyro backup attitude indicators.  There are several hundred of these in existence, as best I can tell.  While the latest "Ultra" models moved over to the Mid-Continent SAM for backup indicators, it seems like this GI275 could fulfill the purpose in our planes that have the standard round instrument gauges.  I've seen a few references to using the device for backup, but it's not clear if this is true with our G1000 models.  Does anybody have the straight skinny on this?  Would it be a drop-in replacement, or does this require some additional approvals from Mooney (God forbid) or otherwise.

Enquiring minds want to know. I did search the main GI275 thread and didn't find any reference to this.  Thanks!

[MIm20c]

Are you looking to just replace the lifesaver AI or all three?  Trying to move it closer or replace the unit on the far right?  Looking to add nav capability?

Edited January 20, 2020 by MIm20c

[mike_elliott]

Let me answer by saying "I dont know"...BUT, it sure makes good sense that you could use it as a backup to your vacuum AI. I suppose a good read of the TC might be in order by your favorite IA.

[Jeff_S]

Thanks Mike.  This non-IA did as thorough a reading as he had the temperament to do of the relevant material. I found the section of the TC that referenced the G1000, which then referenced the relevant sections of 14 CFR Part 23 under which it is certified.  Then I had to REALLY DIG to find an old version of the Part 23 which still had the appropriate paragraph sections (the rewritten Part 23 is totally different...I haven't seen in the literature how this impacts the TC). From there, it seems that 23.1311 (a)(5) is the paragraph that references backup instruments.  It gave me a greater appreciation for why aircraft design and certification is so expensive...I could just imagine myself being a Mooney or Garmin engineer having to wade through every single sentence of that document and then devise a test to prove that it passed certification.  Oy vey!

But I've sent a note off to Trek Lawler through his MS account to see if he can give us the shorthand response...I'll pass along anything I get.

[GeeBee]

At the price they want, why not just buy the G5 unit? Backup battery is better too.

 

[LANCECASPER]

If that's the case it would be nice to get it closer to the pilot.

[carusoam]

Inviting @Deb to the conversation...

David has a G1000 and the ability to remember the fine details required for updating it...   

Best regards,

-a-

[Jeff_S]

Here is the reply from Trek Lawler at Garmin:

"Hello Jeff,

   yes, the GI 275 is an approved backup instrument for the G1000 systems per the details in our STC install manual that you can discuss with your dealer."

 

So there's your answer.  I like the GI275 better because it just fits more aesthetically into that round hole where the current AI is.  As this is one of the last major upgrades I've been considering for my plane (especially now that the STEC 3100 seems to be out of the picture) I will start investigating this more seriously.

[GeeBee]

11 hours ago, philip_g said:

G5 is not certified as a backup.

Gi275 is and should replace all three standby instruments just fine. The cirrus guys are already talking about it for their g1k

No, that is not what is said by Garmin. Garmin says,. the G5 is not a certified backup "Under this STC" meaning Garmin has not included it in their STC. There is no reason you cannot put in a G5 and 337 it under the provisions of AC 91-75 and use the G500 field data as proof. 

[Oldguy]

3 hours ago, GeeBee said:

No, that is not what is said by Garmin. Garmin says,. the G5 is not a certified backup "Under this STC" meaning Garmin has not included it in their STC. There is no reason you cannot put in a G5 and 337 it under the provisions of AC 91-75 and use the G500 field data as proof. 

And a G5 is not approved as a backup for an Aspen, but several on here have had one installed and approved with the proper paperwork. It all seems to depend on whether or not you are working with someone who knows how to document in the manner required to get field approval and is willing to make the effort.

[GeeBee]

4 hours ago, philip_g said:

Good luck with that. And that is exactly, word for word, what Garmin said according to you. 

Not every modification has to be an STC. AC91-75 is pretty clear. The G-5 is just another electric attitude indicator. No different than a lot of other electric AI's with MEMS chips. The FAA would have a hard time turning down the installation of a G-5 while approving an RC Allen 2610. It would violate the spirit and intent of AC91-75 as well as several other FAA safety initiatives. A 337 would be more than enough and as Oldguy says, it is all in how you document it.

Believe me, as part of the SuperCub community for 7 years an STC is not the only way to get things done on a certified aircraft.

 

[Yetti]

The Dynon D10A is STCed for the Mooney M20 line.  45 minute back up battery.   Not sure of the G1000 back up requirements.

[Alan Maurer]

So Guys....Have we decided that is is OK and possible to install a GI 275 in a Mooney that has a G1000 system and remove one or more of the original

three backups on the right side? Like ...for example in  a M20R Ovation??  And would the installation empty one's bank account?

And could these instruments provide data to the autopilot?

thanks

Alan

N913ND

[carusoam]

I believe the answer is yes to all…

The most recent installation manuals should be the resource for all of the answers for the proper back-up to G1000 including the GI-275…

The GI275 is a bit more expensive than the G5…

Installing the Gi275 has plenty of connections…

Should meet your expectations… lots of data, and looks modern too…

Pp thoughts only,

-a-

[GeeBee]

I found out that the G5 STC requires retention of the VSI and some turn rate indication (go figure) and that is why it is not a viable backup for the G1000. The GI-275 has no such requirement and thus is good to go, and I went with it. As to connecting it to the AP that would be great but would require a field approval, a 337 and some switching gear as well as some heading device. Do you like to spend money?

 

 

[LANCECASPER]

2 hours ago, Alan Maurer said:

So Guys....Have we decided that is is OK and possible to install a GI 275 in a Mooney that has a G1000 system and remove one or more of the original

three backups on the right side? Like ...for example in  a M20R Ovation??  And would the installation empty one's bank account?

And could these instruments provide data to the autopilot?

thanks

Alan

N913ND

@Deb has installed a GI-275 in a G1000 Ovation

[EricJ]

32 minutes ago, GeeBee said:

I found out that the G5 STC requires retention of the VSI and some turn rate indication (go figure) and that is why it is not a viable backup for the G1000. The GI-275 has no such requirement and thus is good to go, and I went with it. As to connecting it to the AP that would be great but would require a field approval, a 337 and some switching gear as well as some heading device. Do you like to spend money?

I think those are only requirements if the G5 is used as primary.   The G5 STC does not cover installation as a standby instrument, but Garmin indicates that it is approved as a standby for G500 or G500 Txi systems, probably under the approvals for those devices.   There seem to be a number of G3x installations that use the G5 as standby as well, and as mentioned there are G1000 systems with G5 backups.   There are so many flavors of G1000, though, that approval may be specific to which type, or perhaps they're all done under 337.
 

[Pinecone]

On 1/21/2020 at 11:36 AM, Oldguy said:

And a G5 is not approved as a backup for an Aspen, but several on here have had one installed and approved with the proper paperwork. It all seems to depend on whether or not you are working with someone who knows how to document in the manner required to get field approval and is willing to make the effort.

OK, this explains my, new to me, airplane.

Aspen 1000 PFD.  Garmin G5.  But still have round gauges for Alt, AS, and a T&B

I guess I need to find someone to do the paperwork