Panel/autopilot upgrade advice?

[Amelia]

I treated The Beast, a 1999 M20S with shiny overhauled 550 hp engine, , to a pair of new-and-improved Aspens. I like my legacy Aspen very much, and the upgrades have been waiting on a shelf for installation for months. Now I have reached the end of my rope with the crummy sTec 30 autopilot Tired of throwing good money after bad to repair the thing. So, I am told I can return the unopened new Aspens for a pair of G5s and a Garmin GFC 500 autopilot, which will play nice with my GTN 650. 

But I know nothing about the G5s. ,I know many of y’all are at OSH this week. If you have a minute to browse the offerings in the Avionics building, or offer good advice based on your own experience, I’d be so very grateful!

 

[ArtVandelay]

Or go full glass; G3X & GFC500.

First step is deciding how much you want to spend.

[Amelia]

The old joke about “Exciting women are expensive” has passed its sell-by date.  I need to consider what makes the most sense. Other than sell the airplane, of course. And it looks as if the G3x is only for experimental aircraft.

Edited July 18, 2024 by Amelia

[toto]

12 minutes ago, Amelia said:

The old joke about “Exciting women are expensive” has passed its sell-by date.  I need to consider what makes the most sense. Other than sell the airplane, of course. And it looks as if the G3x is only for experimental aircraft.

Nah, lots of us have a G3X Touch (Certified) and a GFC500 (Certified).  Both are certified versions of the Garmin experimental products.

[LANCECASPER]

So you don't have to cut a new panel a pair of GI275's have a few more features than the G5s

[MikeOH]

@Amelia

Sorry, off topic, but as a VERY happy owner of an STEC-30 for nearly 7 years (no issues whatsoever)...what issues have you had that prompted, "end of my rope with the crummy STEC-30"?  Granted, I may be jinxing myself asking this question...

[Ragsf15e]

I’m curious about your STEC-30 issues too.

If you go garmin, the advice from @LANCECASPERwas spot on. Decide if you want/need a full panel redo.  If you want full glass, do G3x. It’s certified and real nice.  You will have a g5 or gi275 as backup.  If you want a little less surgery/money, you can just install 2xgi275s in the existing ADI and HSI holes.  Either solution will work well with the gfc500.  I have 2xg5s and they are nice, but I got them before gi-275 was available.  Id go that route now.

[Vance Harral]

31 minutes ago, LANCECASPER said:

So you don't have to cut a new panel a pair of GI275's have a few more features than the G5s

This is one of those interesting cases where newer isn't a slam dunk.

GI275s have higher resolution, brighter displays, and features the G5 doesn't.  But whether having more, brighter pixels makes up for the physically smaller size of the display depends to some degree on individual eye performance: focus, whether you need cheaters, etc.  Some people prefer the physically larger square displays over the higher resolution round ones.  So make sure you go actually sit in airplanes with each flavor, before deciding.  You can't really tell how it will affect you personally just from pictures.

You only have to cut the panel for G5s if you want to flush mount them, and that's not a requirement, though you might have to file the hole slightly out of round to get a pair of them to sit one above the other (we did).  But they stick out from the panel quite prodigiously if you don't flush mount - about 3/4".  You don't really notice this sitting right in front of them, but it looks ugly from the side.  If you're a flight instructor in the right seat, non-flush-mounted G5s also tend to obscure the tip of the steam gauge ASI needle when it's in the most interesting part of the range; and if you install only a G5 ADI and keep your steam gauge DG/HSI, the non-flush mount tends to obscure the top of the DG/HSI, which is of course almost the only thing you care about.  Note that the airspeed and altitude tapes on the G5 are not certified primary, and thus are for "situational awareness only", the 275 is superior in this respect.  But when I point this out with my flight instructor hat on, response from the pilot in the left seat is nearly always, "Yeah, whatever..."  I know most of them are completely ignoring the steam gauge ASI/ALT, and it is what it is.

When it comes to battery life, things get really curious.  Garmin advertises 4 hours for the G5, but only 1 hour for the 275.  1 hour is "plenty" by a lot of people's standards, but if you're just comparing runtime, the G5 is the clear winner.  My guess is that high-end display eats a lot of electrons.

Here's a subtle point that's not obvious: the operational knob for the G5 is in the lower right-hand corner of the instrument, while the GI-275 is at lower left.  In a "classic" Mooney 6-pack panel, the yoke shaft exits the panel right next to the 4 o'clock position of the lower center hole, which means the knob for a G5 HSI winds up right next to the yoke shaft, and that's an annoyance for us.  Whether a lower-left or lower-right knob is better varies from airplane to airplane.  Something to think about.

Both devices are wonderful instruments and you can't go wrong with either.  But as I said, not really a slam dunk to choose the newer GI-275, given the cost difference and the subtleties mentioned above.

[toto]

27 minutes ago, Vance Harral said:

This is one of those interesting cases where newer isn't a slam dunk.

GI275s have higher resolution, brighter displays, and features the G5 doesn't.  But whether having more, brighter pixels makes up for the physically smaller size of the display depends to some degree on individual eye performance: focus, whether you need cheaters, etc.  Some people prefer the physically larger square displays over the higher resolution round ones.  So make sure you go actually sit in airplanes with each flavor, before deciding.  You can't really tell how it will affect you personally just from pictures.

You only have to cut the panel for G5s if you want to flush mount them, and that's not a requirement, though you might have to file the hole slightly out of round to get a pair of them to sit one above the other (we did).  But they stick out from the panel quite prodigiously if you don't flush mount - about 3/4".  You don't really notice this sitting right in front of them, but it looks ugly from the side.  If you're a flight instructor in the right seat, non-flush-mounted G5s also tend to obscure the tip of the steam gauge ASI needle when it's in the most interesting part of the range; and if you install only a G5 ADI and keep your steam gauge DG/HSI, the non-flush mount tends to obscure the top of the DG/HSI, which is of course almost the only thing you care about.  Note that the airspeed and altitude tapes on the G5 are not certified primary, and thus are for "situational awareness only", the 275 is superior in this respect.  But when I point this out with my flight instructor hat on, response from the pilot in the left seat is nearly always, "Yeah, whatever..."  I know most of them are completely ignoring the steam gauge ASI/ALT, and it is what it is.

When it comes to battery life, things get really curious.  Garmin advertises 4 hours for the G5, but only 1 hour for the 275.  1 hour is "plenty" by a lot of people's standards, but if you're just comparing runtime, the G5 is the clear winner.  My guess is that high-end display eats a lot of electrons.

Here's a subtle point that's not obvious: the operational knob for the G5 is in the lower right-hand corner of the instrument, while the GI-275 is at lower left.  In a "classic" Mooney 6-pack panel, the yoke shaft exits the panel right next to the 4 o'clock position of the lower center hole, which means the knob for a G5 HSI winds up right next to the yoke shaft, and that's an annoyance for us.  Whether a lower-left or lower-right knob is better varies from airplane to airplane.  Something to think about.

Both devices are wonderful instruments and you can't go wrong with either.  But as I said, not really a slam dunk to choose the newer GI-275, given the cost difference and the subtleties mentioned above.

Very nice analysis.  I went with G5 over GI-275 even though the latter was available, but it's primarily because I prefer the look of the square gauges over the round gauges.  The round gauges make all the sense in the world for a retrofit install where they're replacing a legacy round gauge, but if you're cutting a new panel anyway, the square gauges just look better to my eye.

[NickG]

3 hours ago, Amelia said:

The old joke about “Exciting women are expensive” has passed its sell-by date.  I need to consider what makes the most sense. Other than sell the airplane, of course. And it looks as if the G3x is only for experimental aircraft.

Nope. Here's the panel on my O

[Amelia]

Thank you for your always-helpful thoughts! My problem with the sTec30 is that the nav function doesn’t work at all, and the altitude-hold doesn’t hold. It gradually wanders upward. I miss the glide-slope capture of my old KAP150 in a previous life, and like the idea of a level button within reach of my non-pilot right seater to buy him time to sort things out if I become unuseful. I’ve spent a fair amount on repairs that didn’t work.

My esteemed mechanic notes that the Mooney panel is riveted in, and he’d like to only remove it once, so make up my mind. Then I looked at price tags. Oof! Maybe that wing-leveling sTec can be tolerated after all. And I do like Aspen.

[Falcon Man]

Your first post mentioned you have a "550 hp" shiny engine - maybe your AP isn't up to all that torque! Ha Ha!

[MikeOH]

7 minutes ago, Amelia said:

Thank you for your always-helpful thoughts! My problem with the sTec30 is that the nav function doesn’t work at all, and the altitude-hold doesn’t hold. It gradually wanders upward. I miss the glide-slope capture of my old KAP150 in a previous life,

YIKES!  That's terrible.  Have you spoken with @Jake@BevanAviation, or  @Bob Weber ?  I'd think they could point you towards a solution...well, not for the glide-slope capture!

[Ragsf15e]

19 minutes ago, Amelia said:

Thank you for your always-helpful thoughts! My problem with the sTec30 is that the nav function doesn’t work at all, and the altitude-hold doesn’t hold. It gradually wanders upward. I miss the glide-slope capture of my old KAP150 in a previous life, and like the idea of a level button within reach of my non-pilot right seater to buy him time to sort things out if I become unuseful. I’ve spent a fair amount on repairs that didn’t work.

My esteemed mechanic notes that the Mooney panel is riveted in, and he’d like to only remove it once, so make up my mind. Then I looked at price tags. Oof! Maybe that wing-leveling sTec can be tolerated after all. And I do like Aspen.

Also, when you say “nav function” what do you mean?  If you use the stec to track gps course through a gpss, it should be in heading mode.  In fact, I haven’t used anything except heading in a long time.  I suppose if you were actually going to track to/from a vor or if you want it to track a localizer, you would need a different mode, but otherwise it should be heading.  When gpss is active it will follow the gps.  When it’s not, it follows the heading bug.

The altitude issue is interesting. Mine is real good as long as im trimmed reasonably.  Maybe check with the folks @MikeOH mentioned.  There is a static connection in there feeding the stec “computer”. Wandering off altitude makes me think that’s leaking?

[0TreeLemur]

1 hour ago, MikeOH said:

YIKES!  That's terrible.  Have you spoken with @Jake@BevanAviation, or  @Bob Weber ?  I'd think they could point you towards a solution...well, not for the glide-slope capture!

Agree with this fully.  Earlier this year the KFC-150 in my J was acting up so I took it to a shop, who tried to sell me on a 50 AMU big-G panel upgrade.   Since I had not budget for that, I chose to work with @Jake@BevanAviation , and now my KFC-150 is working great.  All for less than 4 AMUs.  Maintaining a legacy system is a pain sometimes, but since you are active on MS, you care enough to accomplish it.

On the plus side, components of legacy A/Ps are abundant because so many are being removed for big-G upgrades!

[Jake@BevanAviation]

@Amelia A S-Tec 30 system with the ST-901 GPSS convertor if equipped would rarely use a NAV mode unless you wanted to track a VOR/ILS.  You would put your fight plan in on your primary navigator, turn GPSS on for the ST-901 and engage the autopilot in heading mode.  The system would follow the flight plan as if it was tracking a heading bug.  Can you provide additional details about the issue you have with NAV mode?

As for the alt hold function, the system relies on the output of the pressure transducer to provide a correction error for alt hold functions.  The old blue plastic transducer are known to have issues that develop over time.  If it was me I would start by checking the pitch servo start-up voltage and control rigging. Next you would check the static system input to the pressure transducer and the output of the transducer for correction error.  We have seen multiple issues with the blue transducers and static lines that create issues with alt hold tracking.

If you wanted to troubleshoot a Nav track issue you would start by checking the lateral deviation error from the navigator to the S-Tec 30 control head.  As long as you are getting the correct deviation voltage to the control head the navigators are working as intended and the wiring would be ok.  The new step would be to get the control head and roll servo checked. Just like the pitch servo, check the roll servo start-up voltage and control rigging. Unfortunately, S-Tec requires that faulty units be sent in to the factory for repair via a SRO from a current dealer.  There are only very minor field repairs that can be done to the units.  Also, the blue transducer is not repairable if found to be faulty.  You would need a new gold transducer assembly.  If you have questions or concerns about the system just give me a call.

NOTE: the G3x 7" and 10" pfd are approved for the Mooney M20 up to the S model.  Just make sure you have plenty of space as the units are pretty big.

[Pinecone]

7 hours ago, Amelia said:

My esteemed mechanic notes that the Mooney panel is riveted in, and he’d like to only remove it once, so make up my mind. Then I looked at price tags. Oof! Maybe that wing-leveling sTec can be tolerated after all. And I do like Aspen.

Huh??????   never heard of a riveted in panel.  Mine sure was not.

[201Mooniac]

8 minutes ago, Pinecone said:

Huh??????   never heard of a riveted in panel.  Mine sure was not.

Might have meant the rails for the instrument rack.  My plane originally had riveted in rails and the avionics trays were riveted to the rails.

[Pinecone]

That makes sense.

[Amelia]

I wandered out to show this information to John the IA, who has also done some of the stec troubleshooting. He read through Jake’s thoughts item by item, nodding in agreement as he went. Apparently we did all that. So it seems the stec30 either must be tolerated as is or replaced. John would like to send the new, yet to be installed Aspen 2000pro back and replace with two Garmin G5s and, a Garmin 500 autopilot. Claims it’d be solid, capable, simple, work together well with the GTN 650, and last for the rest of my flying life. (I’m OLD!) But, I really like my legacy Aspen, wanted two, and Garmin autopilot won’t play with them. So I ansked about other autopilots. Hate the idea of sTec again, but I already have stec servos, John says the 55X is a nice unit if one is to be found, would allow all the capabilities of the Aspen to be used.

Ohhh, yes, that big screen Garmin would do nicely.  but I’m still looking for oil in my back yard without success.

so, I should have prices and options by Monday. Then the big question will be, will he get the new equipment installed before the September Summit in St Pete? That’s the trouble with having a multitalented mechanic who does it all… everybody else wants stuff done yesterday, too.

[LANCECASPER]

27 minutes ago, Amelia said:

Then the big question will be, will he get the new equipment installed before the September Summit in St Pete?

Depends on which September you’re talking about 

[hais]

On 7/18/2024 at 12:14 PM, Vance Harral said:

You only have to cut the panel for G5s if you want to flush mount them, and that's not a requirement

It is a requirement to get a stamp of approval on MS

[pirate]

Many years ago I had the S-tec 30 with gpss installed and was never really happy with it, seemed to not hold alt or heading very well.
Last year decided to take the plunge and have 2 G5’s and the GFC 500 installed and I have no regrets, night and day difference and really nice on IFR trips

[anthonydesmet]

@Amelia, sorry I didn’t see this post earlier but I wanted to say hello fellow Aspen lover.  Stay the course….plenty of options out there and to keep your Aspen. Especially if you just want basics, shoot an approach (which my K-200) does awesomely.  I also have no oil being pulled from my yard.  A horizons a horizon …..an HSI is an HSI….and last I checked my days of the field moving 30kts away from me pitching and rollover were over so yeah….Aspen is fine.