Garmin dual attitude indicator failures with data

[RobertGary1]

1 hour ago, EricJ said:

I've heard that they have an internal antenna, which in most Mooney panels under the windscreen and glareshield should have reasonable reception.

You have to buy that separately. I may do that although my shop isn’t sure if I’d get good reception with my Mooney panel. Also I’m not sure how I’d know until I need it with my inpanel providing gps fees too. 
the benefit is that it will run off the 275 battery.  If I lose ship power my in panel will die so it would be a gps backup for the 275

Edited May 22, 2021 by RobertGary1

[bradp]

I have a VFR GPS connected to my G5 AI.  It has three sources of GPS for AHRS aiding : 1) 430 2) VFR antenna and 3) bezel GPS antenna.  Signal is fine under the glare shield.  
 

In addition I’ve got a RC Allen electric backup (but no battery), and a GDL52R (again no battery) that feeds AHRS to a panel 660 display.  
 

It’s a fairly robust setup. But I do lack battery backups for my fail safes. 
 

Who was that guy who DER’d dual batteries and dual alternators for a J? 

[smwash02]

3 hours ago, bradp said:

I have a VFR GPS connected to my G5 AI.  It has three sources of GPS for AHRS aiding : 1) 430 2) VFR antenna and 3) bezel GPS antenna.  Signal is fine under the glare shield.  

This is great, but when there's a RAIM failure or GPS interference and we have to fly radar vectors / via VORs and there's an airspeed issue we're going to lose attitude and autopilot driving ability? 

I get it's a somewhat unicorn situation, but quite shortsighted. The yellow box warning idea @N201MKTurbo suggested is a much better solution, in my opinion.

Edited May 22, 2021 by smwash02

[bradp]

Just now, smwash02 said:

This is great, but when there's a RAIM failure or GPS interference and we have to fly radar vectors / via VORs and there's an airspeed issue we're going to lose attitude and autopilot driving ability? 

I get it's a somewhat unicorn situation, but quite shortsighted. The yellow box warning idea suggested is a much better solution, in my opinion.

Yes I went with the garmins specifically because the Aspens had the red x’s everywhere issue with loss of air data aiding.  You’re right this is probably unicorn but simultaneously doesn’t inspire confidence. 
 

Having backups different source / software or mechanical basis (ie vacuum) is the answer.  

[Browncbr1]

33 minutes ago, bradp said:

Yes I went with the garmins specifically because the Aspens had the red x’s everywhere issue with loss of air data aiding.  You’re right this is probably unicorn but simultaneously doesn’t inspire confidence. 
 

Having backups different source / software or mechanical basis (ie vacuum) is the answer.  

I have had two inflight pitot failures in a baron with an Aspen.  Yes, everything red X.  The first time, I made the mistake of trying to cycle power on the Aspen to try to get it to maybe reboot with more data..  it never booted and therefor inhibited transient data to the autopilot and no VS data, so have to climb by CHT reference.

If this happens to anyone with an Aspen, DO NOT turn the Aspen off..  leave it on with red X and make use of your GPSs and altitude hold for the AP.  Otherwise you’re hand flying partial panel.  

[LANCECASPER]

16 minutes ago, Browncbr1 said:

I have had two inflight pitot failures in a baron with an Aspen.  Yes, everything red X.  The first time, I made the mistake of trying to cycle power on the Aspen to try to get it to maybe reboot with more data..  it never booted and therefor inhibited transient data to the autopilot and no VS data, so have to climb by CHT reference.

If this happens to anyone with an Aspen, DO NOT turn the Aspen off..  leave it on with red X and make use of your GPSs and altitude hold for the AP.  Otherwise you’re hand flying partial panel.  

This was prior to the MAX Aspen correct?

[Browncbr1]

46 minutes ago, LANCECASPER said:

This was prior to the MAX Aspen correct?

This unit has not had the upgrade..   most recent failure was earlier this week.  It had 2 or 3 flights since 24m IFR cert.

[LANCECASPER]

Just now, Browncbr1 said:

This unit has not had the upgrade..   most recent failure was earlier this week.  It had 2 or 3 flights since 24m IFR cert.

Ok, I had mine (3) installed in 2018, did the MAX upgrade in 2019. I had a restart on the MFD but it looks like it was a bad cable from the EA-100. So far no problems since.

[Jim Peace]

On 5/21/2021 at 9:51 AM, Ragsf15e said:

So if I lose electrical power in the soup, my battery backup G5s will still have power, but I’ll auger in with a big red X on them because my GPS input will drop and my pitot will ice up with no heat.  Great.

you guys just don't understand...no matter how much money you throw at these planes they are just flying lawnmowers....

[Tom 4536]

18 hours ago, PeteMc said:

By any chance did you start taxiing before you got the 3DDiff?  I don't know about the 275, but there is an Advisory out for the GTN:

Taxiing before the ADS-B GPS source has calculated an acceptable GPS position, will result in an incorrectly transmitted “airborne” Air/Ground status.

Does this apply to rebooting the GPS in the air?

[MikeOH]

2 hours ago, Jim Peace said:

you guys just don't understand...no matter how much money you throw at these planes they are just flying lawnmowers....

Nah, THIS is a flying lawnmower:

 

[RobertGary1]

8 minutes ago, MikeOH said:

Nah, THIS is a flying lawnmower:

 

I’ve got my first cfi-s and just looking for that required second. Then my lessons will start.  Had an intro flight and excited. 

[MikeOH]

11 minutes ago, RobertGary1 said:

I’ve got my first cfi-s and just looking for that required second. Then my lessons will start.  Had an intro flight and excited. 

Briggs & Stratton, or Tecumseh?  

[Ragsf15e]

13 hours ago, jetdriven said:

They don’t 

I have no proof, so there’s that...

However the installation manual for the experimental version refers to the “internal antenna” for the G5.  It goes on to say that you can use the internal antenna as long as you verify reception under the panel or you can use an external antenna or panel mounted gps.  

The experimental and certified G5s are the same, right?

From the intall manual (experimental): “The G5 can receive GPS position information using the unit's internal antenna or by connecting an external antenna. It is recommended to verify the ability of the G5 to receive GPS information via the unit's internal antenna as GPS reception quality is dependent upon the installation (see Section 8.4.13.1 GPS Reception). The G5 will share GPS information with any connected GDU 37X/4XX.”

Edited May 22, 2021 by Ragsf15e

[jetdriven]

38 minutes ago, Ragsf15e said:

I have no proof, so there’s that...

However the installation manual for the experimental version refers to the “internal antenna” for the G5.  It goes on to say that you can use the internal antenna as long as you verify reception under the panel or you can use an external antenna or panel mounted gps.  

The experimental and certified G5s are the same, right?

From the intall manual (experimental): “The G5 can receive GPS position information using the unit's internal antenna or by connecting an external antenna. It is recommended to verify the ability of the G5 to receive GPS information via the unit's internal antenna as GPS reception quality is dependent upon the installation (see Section 8.4.13.1 GPS Reception). The G5 will share GPS information with any connected GDU 37X/4XX.”

I should revise my statement to “They effectively don’t.” 
I had to go looking and it seems that although yes the experimental version, and conversely, the same hardware, the certified version has an internal antenna, certified installation manual makes no mention of this. It says if you want a back up GPS to run a glareshield antenna. So. Learn every  day. 

Edited May 22, 2021 by jetdriven

[David_H]

6 hours ago, Ragsf15e said:

The experimental and certified G5s are the same, right?

It's my understanding (based on conversations with a local avionics shop that sells a significant volume of Garmin equipment) that the certified and experimental versions are indeed the same. The certified version does comes with an extra fancy black envelope with the STC card though.

[David_H]

Before bringing in the MapMX WAAS GPS data via RS-232 from a GTX 335, I tested the internal G5 GPS antenna for position sourcing in a M20F. It appeared to function well during a local flight.

I'm uncertain if the G5 would automatically revert back to the internal antenna if the external WAAS antenna source failed. 

[Ragsf15e]

1 hour ago, David_H said:

Before bringing in the MapMX WAAS GPS data via RS-232 from a GTX 335, I tested the internal G5 GPS antenna for position sourcing in a M20F. It appeared to function well during a local flight.

I'm uncertain if the G5 would automatically revert back to the internal antenna if the external WAAS antenna source failed. 

Unfortunately, I don’t think it’s set up like that, but it seems maybe it should be.  
I think I’m going to test mine with an older Garmin antenna Ive had on the airplane from the last owner, but it’s never been plugged into anything.

[PeteMc]

11 hours ago, Tom 4536 said:

Does this apply to rebooting the GPS in the air?

Just know what the Advisory say, so I would guess so.

I didn't look, but don't they also say that it is not recommended you reboot while airborne and to land as soon as possible...  Or am I thinking of some other device and not the GPS.  

NOTE: Remember the Advisory was for the GTN, I was wondering if it was relevant to the GI275 issue.

[Ragsf15e]

On 5/22/2021 at 11:42 AM, jetdriven said:

I should revise my statement to “They effectively don’t.” 
I had to go looking and it seems that although yes the experimental version, and conversely, the same hardware, the certified version has an internal antenna, certified installation manual makes no mention of this. It says if you want a back up GPS to run a glareshield antenna. So. Learn every  day. 

It seems you are correct about the internal antenna... it’s barely functional.  My G5s can see sky pretty well except for the dash cover and neither got really good reception, although they both achieved a fix.  For a minute the top one flickered to green with an “ok” check mark but it went away.  they see enough satellites but signal strength is low. Some type of external antenna is required.

For the exp version they leave the antenna type wide open, but I think there’s only one approved antenna for the certified version.  Ugh.

[EricJ]

3 hours ago, Ragsf15e said:

It seems you are correct about the internal antenna... it’s barely functional.  My G5s can see sky pretty well except for the dash cover and neither got really good reception, although they both achieved a fix.  For a minute the top one flickered to green with an “ok” check mark but it went away.  they see enough satellites but signal strength is low. Some type of external antenna is required.

...

For the exp version they leave the antenna type wide open, but I think there’s only one approved antenna for the certified version.  Ugh.

I think for certified applications the connection to a gps navigator with a proper external antenna suffices.    I'm not sure that connecting something directly to the G5 for backup purposes is a big issue, especially if it can be removed easily.

 

[Ragsf15e]

37 minutes ago, EricJ said:

I think for certified applications the connection to a gps navigator with a proper external antenna suffices.    I'm not sure that connecting something directly to the G5 for backup purposes is a big issue, especially if it can be removed easily.

 

Fair enough, and I’m pretty sure any reasonable antenna will work, but the G5 install manual only specifies one antenna for certified. Just depends how closely you want to follow it.  I will have to dig around for the cable, but I have an extra antenna on the roof and cable that is looped and secured somewhere in the cockpit... I’d like to give it a try.

[RobertGary1]

1 hour ago, EricJ said:

I think for certified applications the connection to a gps navigator with a proper external antenna suffices.    I'm not sure that connecting something directly to the G5 for backup purposes is a big issue, especially if it can be removed easily.

 

There is speculation that my dual AHRS failure was a result of a gps feed issue. Also if you lose ship power and lose both gps and pitot (icing) you’d lose all AHRS too. Garmin suggested adding local antenna as it will runoff the display battery.  So it’s redundancy  for the AHRS attitude 

 

The AHRS requires external feeds to slew such as pitot or gps. 

Edited May 24, 2021 by RobertGary1

[aviatoreb]

1 minute ago, RobertGary1 said:

There is speculation that my dual AHRS failure was a result of a gps feed issue. Also if you lose ship power and lose both gps and pitot (icing) you’d lose all AHRS too. Garmin suggested adding local antenna as it will runoff the display battery.  So it’s redundancy  for the AHRS attitude 

 

The AHRS requires external feeds to slew such as pitot or gps. 

External antenna?  What item is that and what does it mount on glare shield like a handheld?

[RobertGary1]

22 minutes ago, aviatoreb said:

External antenna?  What item is that and what does it mount on glare shield like a handheld?

At least on the gi-275 it sits right on the glareshield like a handheld. I believe the g5 offers the same but I’ve not seen it.