Directional Gyro Fixes? G5 or ??

sourdough44

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One of the very weak points is my directional gyro, dated, worn, vacuum operated. The whiskey compass isn’t far behind. I get by fine unless a radar facility is giving vectors, which requires plenty of cross checking.

Anyway, I understand the idea of ‘comprehensive’ panel planning, the ‘big picture’. My radios are mostly fine, attitude info pretty good. As with many, trying to keep costs reasonable, since I had extensive engine & airframe work done in recent years.

One initial thought is a Garmin 175 paired to a G5 HSI, soft estimate of $15.5k installed. I do not have a panel mounted GPS, do have the Stratus ESG 3i ADS ‘solution’. I get by with my IPad mini & a few flight apps.

Can one get a G5 put in for just the slaved HSI features but not for any needle steering? I could about live with that, then possible later upgrade with a panel GPS.

I do realize the ‘book solution’ is 2 G5’s paired to a GTN-650, vacuum removed. Just looking at more of the minimalist improvements. Is there a replacement vacuum heading indicator that’s any good? Thanks.
 
What kind of plane? VFR or IFR?

For VFR flight, I'm not sure there is all that much value in replacing a vacuum gyro with glass or removing the vacuum system. If you fly IFR and have a navigator coupled to an autopilot, then there is more significant value in doing so.
 
You will not regret a pair of G5s. The pricing can sting, but they're worth every penny.
 
DA0F8978-7431-4823-BF8E-78EE258C70C3.jpeg It’s a 76 Commander 112. I had a bunch of work done, including a new IO-390 and an MT prop. The engine runs great, like my prop too. I don’t feel the need for 200 & 1/2 but would like to get it IFR capable, even just a GPS.

I know, I need to evaluate things myself. Just trying to find out what I’m missing. I would like to get more to the panel mounted NAV & less so the IPad with apps.
 
I would prioritize IFR GPS and a capable AP over one or two G5s for maximum benefit flying IFR. I'm putting in dual G5s as I write, but I already have the IFR GPS and AP. It's a chunk of change, about $5300 plus 25-ish hours installation, depending. The most time consuming part it finding a suitable spot for the GMU-11 magnetometer. I won't miss the vacuum system.
 
As much as I hate my vacuum pump (don't like a vital component who's most likely failure mode is to stop working with no warning) I'd also prioritize an IFR GPS and an autopilot. There's new Garmin box that does LPV approaches for about 5 grand, if memory serves. For that kind of capability that's chump change. You can't depend on VORs for primary navigation anymore, there's just not enough of them left. But I'd prioritize having my ship properly outfitted for IFR, where there's primary and backup navigation that's calibrated and IFR legal. Use the iPad for situational awareness.

If you're going to plead poverty and fly pirate IFR with your iPad, please have the decency to do it far from me. Autopilots run into big money, but they are nice.
 
There's new Garmin box that does LPV approaches for about 5 grand, if memory serves.
I believe that's the GNX 175 that he mentioned in the original post. If you do that, you will need a compatible indicator to go with it-- or at least you do to fly IFR. If your current indicators aren't compatible with the 175, it's probably cost effective just to go ahead with the G5 HSI. That's what we are doing (although with the GNX 375). Our AI is dying, so we are adding the G5 AI, too, and removing the vacuum system.
 
Yes, leaning GPS-175 & a G5 at the MINIMUM. I’m about ready to commit, shops seem a little busy though.
 
I believe that's the GNX 175 that he mentioned in the original post. If you do that, you will need a compatible indicator to go with it-- or at least you do to fly IFR. If your current indicators aren't compatible with the 175, it's probably cost effective just to go ahead with the G5 HSI. That's what we are doing (although with the GNX 375). Our AI is dying, so we are adding the G5 AI, too, and removing the vacuum system.
Odds are whatever indicator is in the aircraft will not function with an IFR GPS of any stripe. You're saying a G5 works as an IFR legal indicator? Makes it pretty much a no brainier if it is.
 
You're saying a G5 works as an IFR legal indicator? Makes it pretty much a no brainier if it is.

It has been for years.

upload_2019-10-4_8-9-15.png

Within the last 6 months or so the G5 HSI system was STC approved to interface with dual navs, so if equipped with compatible dual navs/gps and a GFC500 they both can display on the G5 and no CDIs will be in the airplane.
 
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Odds are whatever indicator is in the aircraft will not function with an IFR GPS of any stripe. You're saying a G5 works as an IFR legal indicator? Makes it pretty much a no brainier if it is.

Yes, exactly. That's why we are going to put in the G5 in the HSI configuration to replace our current mechanical DG. We need this G5 for legal IFR operations with the GNX 375. Our current indicators won't work with it. But we are keeping them because they work with our current nav radios. So, the dual G5s will be primary navigation indicators when navigating by GPS, but the legacy indicators will be primary for ILS/LOC/VOR. The two G5s will, of course, be primary for pitch, bank and current heading regardless of which NAV source we are using.
 
It has been for years.

View attachment 78409

Within the last 6 months or so the G5 HSI system was STC approved to interface with dual navs, so if equipped with compatible dual navs/gps and a GFC500 they both can display on the G5 and no CDIs will be in the airplane.

I didn't realize that you actually connect the G5 AI to the pitot static system until just recently. When you do that, do you remove the connections to the existing instruments such that the G5 is the only indication of altitude, airspeed and vertical speed, or is the G5 as installed an additional indicator for these?
 
I didn't realize that you actually connect the G5 AI to the pitot static system until just recently. When you do that, do you remove the connections to the existing instruments such that the G5 is the only indication of altitude, airspeed and vertical speed, or is the G5 as installed an additional indicator for these?

No. Its actually a bit of a pain because both G5 and all existing pressure instruments need to be plumbed into the pitot & static.

G5 connections to pitot & static is not optional, its required.
 
No. Its actually a bit of a pain because both G5 and all existing pressure instruments need to be plumbed into the pitot & static.

G5 connections to pitot & static is not optional, its required.

So the G5 serves as a second source and the legacy altitude, vertical speed and airspeed indicators remain functional?
 
So the G5 serves as a second source and the legacy altitude, vertical speed and airspeed indicators remain functional?

Those functions are "advisory" (favorite lawyer BS term) and the existing approved instruments must work to dispatch. The GFC500 envelope protections are using that data directly so its really not "advisory" is it?
 
The physical connections really aren't that big of a deal but installers need to be a little creative to chose a solid & reliable way to hook them all together.

upload_2019-10-4_8-42-29.png
 
Those functions are "advisory" (favorite lawyer BS term) and the existing approved instruments must work to dispatch. The GFC500 envelope protections are using that data directly so its really not "advisory" is it?


Cool. Thank you for the detailed response. I appreciate it.
 
Yes, I just got the one estimate, based on panel pictures, $15.5 or so, one G5 HSI and a Garmin GPS-175. I got this as a baseline to start with & compare. Yes, did seem high.

I’ll take any recommendations, not on the cusp of action anyway right now. I see Jesse here from time to time, where is his shop again? FL? I may do the longer flight & leave the plane if it makes sense, when the time comes.
 
$5k for dual G5’s
$6k for 375
$4k for install

That sounds about right to me.

Single G5 (HSI) and 175 (not 375) - And while $15K sounds about right for dual G5s + 175, it does sound steep for a single G5 + 175. Many avionics shops are quoting high right now because they're so busy. Sarasota in particular is quoting "FU" pricing - For our next upgrade I was expecting about $40K-$45K, and I got a $45K quote from a smaller shop. Sarasota Avionics quoted $80K. Ridiculous.
 
One of the most valuable resources here imho is comparing quoted installation costs, after knowledge sharing of course.
An informed decision on shops is something we might all lack of. It's like knowing an average taxi ride fare in advance, you just know when to pass and say no.
 
Just an update for any interested. A fellow Chicagoland owner is doing a panel upgrade & offered me his ‘old’ vacuum heading gyro, Sigma-Tek 4000C-1. It’s in, I did my test flight this morning. Let me say, it’s about 10+ times better than my old gyro, tracks smooth & holds an accurate heading.

I think I’ll hold off on my G5 thoughts for a while yet.

Thanks a bunch Mark, I’m standing by to reciprocate.
 
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