Instrument Placement Advice for a New Panel (yet another...)

[carusoam]

Out with the TC!

They are a crummy back-up either way….

Then they fail without telling you… they wear and don’t become noticeable… until you need them…

For proof… follow your TC in the bumps… if it is wagging like a happy dog’s tail… it has too many hours on it…

Fantastic plan otherwise… 

Best regards,

-a-

[MMsuper21]

Very curious to see the outcome. Getting the parts ready for mine this is the left hand side panel design in mine: is there a reason not to add some holes? 

 

 

[Seymour]

17 hours ago, carusoam said:

Out with the TC!

18 hours ago, Andy95W said:

if your GI-275s were to fail, you could still fly your airplane VFR, if you keep your altimeter instead of the VSI.

Thanks for these two comments; they caused us to re-evaluate our "already final" panel.  Here's the thoughts:

From our installer, most GI275 installations that keep steam gauges will put ASI over TC, GI275 ADI over GI275 HSI (as req'd by STC) and Altimeter over VSI as Andy noted.  Our decision is to add a third GI275 MFD (for reasons listed earlier).   We feel that the big round VSI is valuable on every flight as an early indicator of issues so we've put it up top.

...so if we're not going to stay Standard-T....

1 hour ago, MMsuper21 said:

is there a reason not to add some holes? 

Good question.  We could simply add a 7th hole and keep the Altimeter.   ...but why?   The tape on the GI275 is easy to read, we already have TWO altimeters (one in each GI275) and they each have battery backup should the ship loose power.   My installer also noted that we'd have to pay $100 every two years at IFR cert check for the steam gauge altimeter (or placard it "VFR Only").   So the final question we ask is the same for all of the steam gauges;  "Do we love it enough that we'd replace it if it busted?".   Unfortunately for the Altimeter, like the vacuum AI the answer is "No".     We do feel strongly about the VSI and ASI.   ....and the TC remains to make a six. 

[ZuluZulu]

Did I read that correctly? $100 every two years is too much to spend to keep the altimeter in a how-many-thousands-dollar panel?! 

[Seymour]

57 minutes ago, ZuluZulu said:

Did I read that correctly? $100 every two years is too much to spend to keep the altimeter in a how-many-thousands-dollar panel?

Nope, you didn't read it correctly.   Andy suggested we keep the altimeter as a "VFR Only" backup.   This panel allows us to eliminate clutter and unnecessary gauges so the question is "Would you replace your THIRD altimeter if it went south?".      We decided the answer was "No", so we pulled it.   

Curious:  What would you do?  Would you keep all of the steam gauges (including vacuum driven AI)?   Where would you draw the line?

[ZuluZulu]

1 hour ago, Seymour said:

Nope, you didn't read it correctly.   Andy suggested we keep the altimeter as a "VFR Only" backup.   This panel allows us to eliminate clutter and unnecessary gauges so the question is "Would you replace your THIRD altimeter if it went south?".      We decided the answer was "No", so we pulled it.   

Curious:  What would you do?  Would you keep all of the steam gauges (including vacuum driven AI)?   Where would you draw the line?

Since you asked: I would install a 10" G3X Touch instead of three GI-275s, with either a GI-275 or G5 as the backup.

[Seymour]

9 minutes ago, ZuluZulu said:

Since you asked: I would install a 10" G3X Touch instead of three GI-275s, with either a GI-275 or G5 as the backup.

Reasonable.   ...but would you retain any steam gauges?   ( ...and it would have to be the G5 for backup with the G3X; that's a restriction with the AP.)

G3X is a great choice, especially if you don't already have an EIS.  

[ZuluZulu]

8 minutes ago, Seymour said:

Reasonable.   ...but would you retain any steam gauges?   ( ...and it would have to be the G5 for backup with the G3X; that's a restriction with the AP.)

G3X is a great choice, especially if you don't already have an EIS.  

No, I would not.  If I really wanted a non-Garmin backup I'd get a MidContinent SAM.  I currently have two G5s but am planning to go full glass in the next five years or so.

Is the G5 the only permitted backup when installed with a GFC 500?  The G3X and GI-275 can both drive the GFC 500 so I'm surprised to hear you must go with the G5 over the better-featured GI 275.  

[Seymour]

1 hour ago, ZuluZulu said:

Is the G5 the only permitted backup when installed with a GFC 500?  The G3X and GI-275 can both drive the GFC 500 so I'm surprised to hear you must go with the G5 over the better-featured GI 275.  

I'm searching for the thread where Skip @PT20J recently detailed the reason the G5 must be used as backup, but I'm inept at MS search.  (For some reason, Club name is sticky and it's only searching in that club).  

 

Edit:  Found one mention here but still looking for the full explanation.  I may have misunderstood something Skip wrote.

 

Edited March 29, 2022 by Seymour
Pointer to another thread

[carusoam]

8 minutes ago, Seymour said:

I'm searching for the thread where Skip @PT20J recently detailed the reason the G5 must be used as backup, but I'm inept at MS search.  (For some reason, Club name is sticky and it's only searching in that club).  

Stand by for Skip to come by…

But, in the meantime…. Each device has a list of eligible back-ups…. The list is found in the install manuals….  And install manuals get updated often, adding to the list…

Make sure you have the latest copy of the install manual when checking the list….

 

The G3X and the G5 are designed and built by the same organization inside Garmin… (the experimental group)

The GI275 is in a different group….

So… things you expect to be able to be a back-up… may not have been tested or designed or have some weakness… or just didn’t get on the list…

 

PP thoughts only, no where as knowledgable as Skip on this subject…. 

Best regards,

-a-

[PT20J]

Both the G5 and GI 275 are approved by the Garmin STC as backups for a G3X. However, the G5 is integrated with the G3X and the GI 275 is not. So, if you install a G5, the G3X will use the G5 ADAHRS if the GSU 25D fails and the G5 can use the external navigator (i.e., a GNS or GTN) and also drive the GFC 500 if the G3X fails. In the case of the GI 275, the STC requires that it not be connected to an external nav source and it is not integrated with the G3X or GFC. In other words, it’s just an expensive stand alone attitude indicator with altimeter, airspeed and heading.

Skip

[carusoam]

Skip, you and your skill set are both awesome!   
 

See if @Seymour is cruising by…

-a-

[PT20J]

13 minutes ago, carusoam said:

Skip, you and your skill set are both awesome!   
 

See if @Seymour is cruising by…

-a-

Thanks, Anthony. It would be easier if Garmin didn’t bury important details in the secret installation manual. Here’s the details…

[0TreeLemur]

7 hours ago, MMsuper21 said:

Very curious to see the outcome. Getting the parts ready for mine this is the left hand side panel design in mine: is there a reason not to add some holes? 

 

 

Did that.  Where you have "CLOCK" we put in an AV-20, which is an excellent clock, timer, and backup AI.

 

 

[MMsuper21]

6 hours ago, 0TreeLemur said:

Did that.  Where you have "CLOCK" we put in an AV-20, which is an excellent clock, timer, and backup AI.

 

 

Thanks, for the pm and Av20 is arriving Wednesday  @0TreeLemur

I am mainly concerned about the GI 275 as AI. Once the panel is flat we loose almost 1 inch. The Garmin install doc calls for 6.44inches plus pluming. There is also the window defroster line hook up on top behind the panel that might interfere. 

Even as the HSI it would be getting close to the steering column. (Avionics shop is pushing the G5 only 3.5 inches deep less if not flush) Maybe he is being lazy. 

 

[MMsuper21]

11 hours ago, Seymour said:

Nope, you didn't read it correctly.   Andy suggested we keep the altimeter as a "VFR Only" backup.   This panel allows us to eliminate clutter and unnecessary gauges so the question is "Would you replace your THIRD altimeter if it went south?".      We decided the answer was "No", so we pulled it.   

Curious:  What would you do?  Would you keep all of the steam gauges (including vacuum driven AI)?   Where would you draw the line?

Can’t find it here but just read about the dual gi275 failure (and they were setup wrong and did not fail over, make sure to test the install) one of the probable causes was the electrostatic charge through the clouds. Plus our magnetic cages and Murphy seems to like me. 

As for the Vac I will be keeping mine anyways for the PC, don’t have an autopilot.

I prefer to keep mechanical rather independent backups. 

[Seymour]

@PT20J  Thanks for the clarification, Skip!   

You're very generous responding inquires and sharing your valuable Garmin post-install check lists.    They can save us AMU (and possibly our lives).  

[PT20J]

2 hours ago, Seymour said:

@PT20J  Thanks for the clarification, Skip!   

You're very generous responding inquires and sharing your valuable Garmin post-install check lists.    They can save us AMU (and possibly our lives).  

No problem. We all help each other. I’ve certainly learned a lot from others here.

Skip

[carusoam]

MM,

Use caution with instrument spacing…

There are two layouts for the eight pack…

One has an extra inch between the middle column… (or so)

 

I bet the older layout, with the extra space… may be related to the two different sets of yoke shafts that have vertical motion as they go in and out…

Scan a few pics of panels around here… you will see an unexplained extra space in some… 

 

Panel design quickly becomes a 3D sport when it comes to real planes….

First lesson is often the inverted Y, tube structure…

Second lesson is often the yoke has vertical movement on the other side of the panel…

 

Some people mock up their panels in acrylic before committing to the final version…

This way you get a window on the world behind the panel…

 

PP thoughts only, not a mechanic…

Best regards,

-a-

[Mooney in Oz]

On 3/29/2022 at 10:46 PM, MMsuper21 said:

Can’t find it here but just read about the dual gi275 failure (and they were setup wrong and did not fail over, make sure to test the install) one of the probable causes was the electrostatic charge through the clouds. Plus our magnetic cages and Murphy seems to like me. 

As for the Vac I will be keeping mine anyways for the PC, don’t have an autopilot.

I prefer to keep mechanical rather independent backups. 

Transport Canada investigation:

https://www.tsb.gc.ca/eng/rapports-reports/aviation/2021/A21P0001/A21P0001.html

The word frightening understates what this pilot went through.

MS thread:

 

[carusoam]

Call that the @RobertGary1 experience…

Nobody would like to repeat that….

Very interesting TC report, thanks for posting it here…

Best regards,

-a-

[Seymour]

On 3/30/2022 at 12:56 AM, carusoam said:

Panel design quickly becomes a 3D sport when it comes to real planes….

First lesson is often the inverted Y, tube structure…

Second lesson is often the yoke has vertical movement on the other side of the panel…

Good call Anthony.   

 

@MMsuper21  My Super 21 is a 1965 model (built in 1964).   There's a reason old Mooneys have the shotgun layout in the first place.   If you have the same vintage, I suspect your layout won't work.   The result for mine is that the center two gauges (the GI275 ADI over the GI275 HSI in my diagram) will be about 2 inches higher than the other 4 instruments.    ...so it will be functional, but not fully aligned horizontally.   

From our installer:

"physical positioning of the instrument holes cannot be straight across as your drawing shows. ... The reasons for this are 4-fold despite obtaining a (0) zero degree panel tilt:
1) The AI/HSI must be higher to avoid the yoke column (plus optimum viewing)
2) The MFD cannot go as high because of a defroster duct obstruction but might be able to go a bit higher than pictured but ref #4
3) The VSI cannot go as high due to the curvature of the panel.
4) For aestethic reasons, balancing the VSI/AS height and the MFD/TC columns is desireable.
 
There really is no choice in this....just letting you know."

 

 

[rbp]

This the Garmin G5 with the Master and Battery Master turned off, and operating on battery (5 hours 46 minutes)

You'd really rather keep your vacuum system???

[rbp]

This is (most of) what came out: 

(sandel substituted for King AI which was sold)

[MMsuper21]

Pretty sure my yoke has vertical movement...

Thanks for the info @carusoam Hendricks mfg is doing the panel for me, I should do the acrylic mock up. I do recall seeing the ADI/DG moved up on some panels. 

@0TreeLemur looks like you made it line up and fit somehow. Looks like its fine without the GI275. 

The other option is doing the AV30s or G5s half the depth and AMUs.