AP options for an early J?

[BlueSky247]

You guys might find this interesting. I filled out S-tec's web form the same day I started this thread. I just got this reply from them:

 

"The 55X is a great option for your Mooney. It is a 2-axis coupling autopilot that includes vertical navigation, GPSS and GS capture. Auto Trim and Altitude Preselector are two additional options."

Based on some cursory searches, and unless I'm missing something, I'm not seeing a compelling price delta for choosing to go a different path with those guys. (vs the gfc500)

 

[LANCECASPER]

1 hour ago, BlueSky247 said:

"The 55X is a great option for your Mooney. It is a 2-axis coupling autopilot that includes vertical navigation, GPSS and GS capture. Auto Trim and Altitude Preselector are two additional options."

Twenty years ago that may have been true.

If you already had an STec 55X you might want to keep it, but no one would never spend the money today on installing one unless it was the only autopilot available for a particular airframe.

[toto]

Just now, LANCECASPER said:

Twenty years ago that may have been true.

If you already had an STec 55X you might want to keep it, but no one would never spend the money today on installing one unless it was the only autopilot available for a particular airframe.

Technically you could still buy the Century 2000 that came in my a/c brand new today for $30,000 plus installation.  I've always been mystified about why Century has these listed for sale on their website, but maybe there's some aircraft out there somewhere that isn't on any AML for a modern autopilot and has the Century 2000 on the type certificate.

[LANCECASPER]

3 minutes ago, toto said:

Technically you could still buy the Century 2000 that came in my a/c brand new today for $30,000 plus installation.  I've always been mystified about why Century has these listed for sale on their website, but maybe there's some aircraft out there somewhere that isn't on any AML for a modern autopilot and has the Century 2000 on the type certificate.

Technically they went out of business a few years back.  Their website was still up for awhile but recently it went down.  https://www.centuryflight.com/

[BlueSky247]

I replied back to s-tec asking if they could forward the technical installation information for their system, just to try to get a sense of what it would involve.  "I can't send you that as it is controlled information, but you can expect about 70 hours for the installation."

 

 

[LANCECASPER]

3 minutes ago, BlueSky247 said:

I replied back to s-tec asking if they could forward the technical installation information for their system, just to try to get a sense of what it would involve.  "I can't send you that as it is controlled information, but you can expect about 70 hours for the installation."

 

 

If you buy a used STec you have to buy the technical info plus STC from them for several thousand dollars

 

For a Mooney your two viable options are:

Bendix King Aerocruze 100 (https://duncanaviation.aero/news/duncan-aviation-has-stc-to-install-bendixking-aerocruze-100-autopilot-in-mooney-m20s)  Very shaky company support

or a Garmin GFC500.

 

You don't want to spend $5000 - $10,000 labor to install a used autopilot that someone had the good sense to remove from their airplane. It's another thing to buy used parts to keep an autopilot in good repair. 

[toto]

15 minutes ago, LANCECASPER said:

Technically they went out of business a few years back.  Their website was still up for awhile but recently it went down.  https://www.centuryflight.com/

Ha, okay - I clearly haven't been there in a while

 

[BlueSky247]

I was just wandering around on the Dynon site and found this page:

 

https://www.dynoncertified.com/upcoming-approvals.php

 

So yea, maybe it's BS or will be years away, but the Mooneys being first in line and that progress bar sitting around 70% sure does look nice. 

[NickG]

On 7/4/2024 at 8:22 PM, EricJ said:

^^I think this is correct.   I fly regularly with a buddy who has an Aerocruz in his Cherokee, and I fly safety pilot for him when he does his IFR currency approaches.   It'll fly the approach quite well, but you're not supposed to.   Great to have in a pinch. 

They're good autopilots.

I had an Aerocruz 100 in my Cherokee 235. It’s a fine little autopilot - will only fly heading mode (when coupled to an appropriate source such as a G5), track mode using its INTERNAL GPS, or GPSS mode when coupled to a GPS navigator. It will not fly an ILS approach or anything other than GPS. It’s is NOT certified for coupled approaches (although as mentioned it will perform that task - just not legal). BK Aerocruz has no auto trim (it does on the experimental version), and you’re constantly retrimming. It had difficulties tracking in anything greater than light turbulence. Having said that, it is a perfect little unit that does the job at a reasonable price.

I have a GFC-500 in my O. You cannot really compare the two autopilots. The GFC-500 is a full featured autopilot, will fly just about any approach you can find, has VNAV and a whole range of advanced features.

If GPS is spoofed or jammed, neither autopilot will be able to function with its full feature set.

It’s really just a question of budget. If you have the budget and are willing to spend it  for the GFC-500 then that is clearly the best autopilot in terms of features, etc. If you have a smaller budget, then Aerocruz 100 is a good choice that you will be happy with. Just know what the capabilities are so you are not disappointed.

Garmin replaced the servos in my O 3 years ago and they have worked beautifully ever since with no issues whatsoever.

[Rogerg]

FWIW I have a Dynon auto pilot in my 1985 m20j and have had for a few years now (in Australia this is permitted using an engineering order).

The dynon autopilot is a sensational.

It has handled some horrible turbulence for extended periods without ever disconnecting.  It flys approaches better than most autopilots (and i have used most of the common ones).  Its accuracy is very very good.   

Hopefully the Dynon get the approval done soon - you will love it

 

 

 

[NickG]

On 7/4/2024 at 4:45 PM, LANCECASPER said:

6. If the GPS signal is lost, for whatever reason, obviously a coupled GPS approach can't be flown with any autopilot. But on the GFC500 even a coupled ILS approach isn't possible with loss of GPS signal.  While I agree that no competent IFR pilot should need to fly a coupled approach, a coupled alternate approach is nice option after a long cross country flight in IFR. This is a design limitation that is not understood by many people looking to buy this autopilot, and by some people who already own this autopilot. I wouldn't want to be in the soup at a minimum IFR fuel reserve discovering this. 

BK Aerocruz won’t fly a coupled ILS approach, period.  It has track mode, which uses its internal GPS, heading mode which it will pull off of a coupled G5, GI 275, Aspen, Dyson and GPSS mode which its gets from your GPS navigator. It GPS Signal is lost, BK Aerocruz will only work on heading mode.

[NickG]

On 7/3/2024 at 7:58 PM, EricJ said:

1.   Garmin says it has to be installed by a dealer.   I can install the BK, and so can any competent avionics tech or shop.   

2.  The BK Mooney installations that have been have been done have been reportedly quite straightforward and relatively simple.   In other words, much less labor than the Garmin.

3.  I like the pushrod servos like S-Tec, Century, BK Aerocruz, and (IIRC) Dynon use.   Garmin elected to use cable servos in a pushrod airplane (like King).   The GFC installation in the wing strikes me as a Rube Goldberg arrangement of brackets and pulleys, none of which appear to need to be there, and the contraption that they add to the tail is, to me, worse.

4. The installed base doesn't have a great history so far for servo longevity, which kind of continues the Garmin servo reputation.   And when they fail they're expensive if they're out of warranty.

5. There still seems to be a lingering issue with pitch stability for the GFC500 in the Mooney.    I haven't heard any similar issues with the installed Aerocruz, but the installed base is still small.   I've asked everyone I've run across that got one installed and have yet to hear anything negative.

 

 

Eric, the BK 100 needs to constantly be trimmed manually. It tracks poorly in turbulence and you need to make sure the ball is caged because it’s not that great if you’re uncoordinated (of course, you shouldn’t be anyway). Anyhow, all that considered, it’s a decent AP for the $$. I hear good things about the TRIO although my understanding is that installation is more labor intensive and I’m not sure it’s certified for Mooneys anyhow. The Dyson AP will be an exciting option if and when they finally certify it for your bird. Good luck!

[BlueSky247]

@Rogerg I had no idea it was in already in operation in other countries. That is awesome! Thanks for that. 

[LANCECASPER]

1 hour ago, NickG said:

BK Aerocruz won’t fly a coupled ILS approach, period.  It has track mode, which uses its internal GPS, heading mode which it will pull off of a coupled G5, GI 275, Aspen, Dyson and GPSS mode which its gets from your GPS navigator. It GPS Signal is lost, BK Aerocruz will only work on heading mode.

I agree 100%, but you aren't expecting the Aerocruze to do that either.

What concerns me is that I have talked to more than a few who own a GFC500 that aren't aware of losing the coupled ILS if they lose their GPS signal. I have had a couple of them adamantly argue about it until seeing it in writing. I would hate to find out about that limitation in a high stress,  actual IMC, diverting to alternate, low-fuel situation. If you know about the limitation and you're prepared for it, not a big deal, but confusion and high stress are not a good combination. 

[PT20J]

The shop can print out the AFMS but they can’t make the pilot read it.

[NickG]

43 minutes ago, LANCECASPER said:

I agree 100%, but you aren't expecting the Aerocruze to do that either.

What concerns me is that I have talked to more than a few who own a GFC500 that aren't aware of losing the coupled ILS if they lose their GPS signal. I have had a couple of them adamantly argue about it until seeing it in writing. I would hate to find out about that limitation in a high stress,  actual IMC, diverting to alternate, low-fuel situation. If you know about the limitation and you're prepared for it, not a big deal, but confusion and high stress are not a good combination. 

Yes. Absolutely. The GFC500 will disconnect ILS tracking if GPS is lost during the ILS, although the HDG, VS etc modes remain available. The GFC600/700 will not disconnect but you get degraded performance.

[LANCECASPER]

43 minutes ago, NickG said:

Yes. Absolutely. The GFC500 will disconnect ILS tracking if GPS is lost during the ILS, although the HDG, VS etc modes remain available. The GFC600/700 will not disconnect but you get degraded performance.

I agree with you on the GFC500. Here's the AFMS for a Cessna 182: https://static.garmin.com/pumac/190-02291-06_01.pdf

 

I don't see any mention of degraded performance for loss of GPS during an ILS for a GFC600 in the AFMS for a Cessna 182: https://static.garmin.com/pumac/190-02011-02_01.pdf

Nor do I see any mention of degraded performance for loss of GPS during an ILS in the GFC700 AFMS for the Acclaim. 

[NickG]

6 minutes ago, LANCECASPER said:

I agree with you on the GFC500. Here's the AMFS for a Cessna 182: https://static.garmin.com/pumac/190-02291-06_01.pdf

 

I don't see any mention of degraded performance for loss of GPS during an ILS for a GFC600 in the AMFS for a Cessna 182: https://static.garmin.com/pumac/190-02011-02_01.pdf

One reason may be that it has its own internal AHRS. 

Interesting. The info that I posted came from Garmin… but I don’t see any mention of degraded performance in the GFC600 AMFS link you provided either…..

[NickG]

40 minutes ago, PT20J said:

The shop can print out the AFMS but they can’t make the pilot read it.

So very true. Sad, but true.

[LANCECASPER]

For a few reasons many of us had hoped that the GFC-600 would have been approved for Mooneys, like it was for some Cessnas, Pipers and Beechcraft singles.

https://mooneyspace.com/search/?q=GFC-600&quick=1

https://mooneyspace.com/search/?&q=GFC600&quick=1&search_and_or=or&sortby=relevancy