Reading through Whee's thread on glass panel recommendations got me thinking about what to do about an attitude indicator in my plane.

I pulled my vacuum system out during the rebuild because the AI and DG both need an overhaul, and they are bricks... My plane is not IFR and never will be, but I think I would like to have something to point me up in the event I ever needed it.

I have been flying exclusively with an iPad running Garmin Pilot and WingX, and my first thought was to get the GDL 39 3D so that I have attitude and a synthetic vision display (SV on Garmin only because the WingX terrain database does not cover most of Alaska). I have never had reliability or glare problems, but have heard all about it...

Another thought is to get a Dynon D2 which will also drive an attitude display on WingX, but I wouldn't have synthetic vision or ADS-B.

I just found the GRT Mini-GA,http://www.grtavionics.com/mini-ga.html, which is a similar concept to the Dynon D2, but it has a map and terrain database and will show synthetic vision but still no ADS-B.

I would sell a Garmin 496 to fund one of these options. I have never flown with it, so I could be missing out.

What say the group? Should I keep the 496 and go without attitude (not likely to happen), or sell it and get one of the options? Did I miss anything, within a similar price point of about $1,500?

The GLD 39 3D "attitude function" is dangerous to use. It's definitely "beta" technology. Would NEVER NEVER trust it IFR, REPEAT NEVER.

I flew this summer up to SE Alaska (VFR low and slow) and only used ADSB (USA) and GPS (USA CAN). GLD 39 3D worked great for those.

I love my little Castleberry electric...

You probably saw my post about the D2 in Whee's thread, so I won't rehash it, but it has been very impressive in some really poor visibility situations and I wouldn't hesitate to buy one again, and customer support has been great. The Mini-GA looks good and it does more (costs more) don't have any experience with GRT. The 496 has been a good unit, but I agree, its now a backup for me with the ipad.

Chris

For emergency (IE never use it for real unless you've made at least 9 bad decisions in the last 20 minutes)

Ipad ForeFlight and a stratux.
http://www.eaa.org/en/eaa/aviation-comm ... -than-$120

They are really really close to having AHRS support for it.

I built one from amazon and had it running in 5 minutes.

I'm playing with adding a 3.5" screen and running my own homebuilt UI on it.
Dynon D2 for $150 smakers.

But again... Using or relying on any of these in real life IFR is about as smart as buying bolts at Home Depot for your engine mount.

Trutrak ADI is electronic and gives you mag heading from a GPS. A nice round gauge that looks old school and performs very well.

8GCBC wrote:The GLD 39 3D "attitude function" is dangerous to use. It's definitely "beta" technology. Would NEVER NEVER trust it IFR, REPEAT NEVER.

I flew this summer up to SE Alaska (VFR low and slow) and only used ADSB (USA) and GPS (USA CAN). GLD 39 3D worked great for those.

I love my little Castleberry electric...

http://www.aircraftspruce.com/pages/in/ ... ca2600.php

Does anyone have an opinion about these solid state devices? It's only $200 more than your Castleberry, but should be much lighter, and has fewer failure modes.

hpux735 wrote:

8GCBC wrote:The GLD 39 3D "attitude function" is dangerous to use. It's definitely "beta" technology. Would NEVER NEVER trust it IFR, REPEAT NEVER.

I flew this summer up to SE Alaska (VFR low and slow) and only used ADSB (USA) and GPS (USA CAN). GLD 39 3D worked great for those.

I love my little Castleberry electric...

http://www.aircraftspruce.com/pages/in/ ... ca2600.php

Does anyone have an opinion about these solid state devices? It's only $200 more than your Castleberry, but should be much lighter, and has fewer failure modes.

I like gyros that are certified! They wear out fast sometimes, and are freeking expensive too.

Bottom line: I will only use gyros for "real" attitude flying. Old school boy here.

Note: RC Allen makes stinking trash, opinion.

8GCBC wrote:

hpux735 wrote:

8GCBC wrote:The GLD 39 3D "attitude function" is dangerous to use. It's definitely "beta" technology. Would NEVER NEVER trust it IFR, REPEAT NEVER.

I flew this summer up to SE Alaska (VFR low and slow) and only used ADSB (USA) and GPS (USA CAN). GLD 39 3D worked great for those.

I love my little Castleberry electric...

http://www.aircraftspruce.com/pages/in/ ... ca2600.php

Does anyone have an opinion about these solid state devices? It's only $200 more than your Castleberry, but should be much lighter, and has fewer failure modes.

I like gyros that are certified! They wear out fast sometimes, and are freeking expensive too.

Bottom line: I will only use gyros for "real" attitude flying. Old school boy here.

Note: RC Allen makes stinking trash, opinion.

Just commenting, not arguing. The RC Allen solid state AIs are certified. Also FWIW, I have an RC Allen "old school" AI in my airplane; it's been there 11 years, and still works fine.

Cary

Cary wrote:
Just commenting, not arguing. The RC Allen solid state AIs are certified. Also FWIW, I have an RC Allen "old school" AI in my airplane; it's been there 11 years, and still works fine.

Cary

I'm glad you had a better experience than me! Seems like you have a good product from RC Allen.

10 years ago...

I bought a terrible RC Allen electric gyro (certified) for a backup. The gyro never held attitude correctly. Lots of errors, it was scary. Sent it back and filed an SDR with the FAA.

First of all, I'm sorry to the OP if I've caused the this thread to drift to the point that it's this is useless information. But, I recently read that there was a rule change that lets you (potentially) remove all the vacuum parts from your plane and go all-electric. This is cool to me because the vacuum pump MTBF is something like 500 hours, a vacuum-driven AI is around 1000 hours, and an electric gyro AI is a few 1000 hours. A solid-state gyro is more likely to be in the neighborhood of 10,000-100,000 hours. In addition, it'll weigh less, and won't have the parasitic load on the engine. Personally, I'm only interested in devices certified for primary instrumentation, because that's the only way to get rid of the vacuum system on a certified plane.

http://www.avweb.com/news/redundant/Dum ... 627-1.html

Has always been two separated power sources. Can be electric backup too.

8GCBC wrote:The GLD 39 3D "attitude function" is dangerous to use. It's definitely "beta" technology. Would NEVER NEVER trust it IFR, REPEAT NEVER.

I love my little Castleberry electric...

Thanks for this info. I have been leaning away from the GDL because it does not have an adjustment to compensate for deck angle on the ground vs in flight. Whatever angle it is powered on at is the straight and level mark, so in a tailwheel you have to get flying straight and level then hit a button to cage the display.

I like the castleberry, and some of the other back-up attitude indicators but they are generally 1 or more AMUs out of my price range. Im going to have to stick with a "portable device".

slowhawk wrote:You probably saw my post about the D2 in Whee's thread, so I won't rehash it, but it has been very impressive in some really poor visibility situations and I wouldn't hesitate to buy one again, and customer support has been great. The Mini-GA looks good and it does more (costs more) don't have any experience with GRT. The 496 has been a good unit, but I agree, its now a backup for me with the ipad.

I did see that, and that is what got me started thinking about this. That is a good pirep, I wish I could check out both of them before I buy.

hpux735 wrote:Personally, I'm only interested in devices certified for primary instrumentation, because that's the only way to get rid of the vacuum system on a certified plane.

Your point makes sense, but if your plane never had a vac system...

Prosaria Thu Oct 22, 2015 12:11 am wrote:
Thanks for this info. I have been leaning away from the GDL because it does not have an adjustment to compensate for deck angle on the ground vs in flight. Whatever angle it is powered on at is the straight and level mark, so in a tailwheel you have to get flying straight and level then hit a button to cage the display.

I like the castleberry, and some of the other back-up attitude indicators but they are generally 1 or more AMUs out of my price range. Im going to have to stick with a "portable device".

Testing my memory...I am away from the unit...

I believe there is a synthetic attitude indicator "reset" on the GDL 39 3D ( Pilot software ). But, it is not reliable.

http://static.garmin.com/pumac/190-11110-00_0H_Web.pdf wrote:4.6 Attitude Heading Reference System (AHRS)
This section only applies to the GDL 39 3D units with the AHRS function. The AHRS function starts automatically and will perform leveling adjustments for pitch and tilt angles when the unit is powered on. The AHRS function will not be available until the leveling process has finished. The GDL 39 3D does not have to be perfectly level as the leveling process will compensate for any differences. The connected display device can command the GDL 39 3D to perform the leveling process.

8GCBC wrote:Testing my memory...I am away from the unit...

I believe there is a synthetic attitude indicator "reset" on the GDL 39 3D ( Pilot software ). But, it is not reliable.

Interesting, so you can fire it up in a tailwheel and go fly without having to tell it to re-level (assuming it were reliable)? This is how it should be, but I have been hearing that this is not the case.

Prosaria wrote:

8GCBC wrote:Testing my memory...I am away from the unit...

I believe there is a synthetic attitude indicator "reset" on the GDL 39 3D ( Pilot software ). But, it is not reliable.

Interesting, so you can fire it up in a tailwheel and go fly without having to tell it to re-level (assuming it were reliable)? This is how it should be, but I have been hearing that this is not the case.

No, it simply does a reset.

If I remember the aircraft has to be straight and level (non accelerated) then Garmin Pilot does a software reset. Similar to caging a gyro to level flight after precession i.e. steep turns.

Very basic "beta" technology, opinion.

hpux735 wrote:....Personally, I'm only interested in devices certified for primary instrumentation, because that's the only way to get rid of the vacuum system on a certified plane........

I assume that you're talking about for IFR use. The vacuum horizon & DG on both my old C170 & my old C150/150TD were optional per the factory equipment list, and I removed all that junk on both of them. They're also optional on my 1953 C180, and I've thought of pulling them out of this one also, but since it's more of a traveling machine I would like to have something "just in case". A Dynon D2 fits the bill for being light, simple, long-lifed, and also for having a bunch more tricks up it's sleeve than just attitude. It is also Wi-Fi capable so that the D2's GPS can feed a sectional-based moving map display on an ipad or similar. I don't have one now, but I might get one in the future to replace / supplement my G196.

For use as a true backup VFR attitude indicator, the Dynon D1 has worked very well for me in my Husky with no vacuum system. It is ridiculously light and accomplishes the objective.

Squash wrote:For use as a true backup VFR attitude indicator, the Dynon D1 has worked very well for me in my Husky with no vacuum system. It is ridiculously light and accomplishes the objective.

Good enough for me. I am going to sell the 496 and pick up a Dynon D2. The GRT looks great, but I really don't NEED all fancy stuff as much as I just want it...

Do you have the D1 mounted in an instrument hole or somewhere else? I am wondering how it will fit into a six pack in place of my AI.

Can the D2 also be used in place of a DG? On my flight today mine went tits up. Just spins round and round. So wondering if I can get rid of my vacuum system and guage right away as well...

A1Skinner wrote:Can the D2 also be used in place of a DG? On my flight today mine went tits up. Just spins round and round. So wondering if I can get rid of my vacuum system and guage right away as well...

The D2 only gives you GPS ground track. The GRT unit I talked about above will act as a DG independent of the GPS with a remote magnetometer.