AP options for an early J?

[EricJ]

6 minutes ago, toto said:

I don’t think the Aerocruze has been approved for coupled approaches. So the AP will *fly* a coupled approach, but it’s prohibited by the AFMS.

^^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.

[toto]

2 hours ago, PT20J said:

That is clearly described in the AFMS. (Everybody reads that before buying, right?) The G3X VFR GPS will provide sufficient GPS position to the autopilot in the event my GTN fails (Garmin confirmed it and I verified it in flight). So, it’s only interference or failure of the GPS constellation that would be an issue. 

This is interesting. My AFMS is vague on the GPS source, and doesn’t clearly say whether the source must be an approach certified GPS or not. If your GTN GPS fails and the GFC begins using the G3X GPS, do you need to take a manual action to restore approach mode?

[ArtVandelay]

This is interesting. My AFMS is vague on the GPS source, and doesn’t clearly say whether the source must be an approach certified GPS or not. If your GTN GPS fails and the GFC begins using the G3X GPS, do you need to take a manual action to restore approach mode?

I assume “gps navigator” in the AFMS implies certified GPS.

[toto]

12 minutes ago, ArtVandelay said:

I assume “gps navigator” in the AFMS implies certified GPS.

Maybe. The scenario @PT20J is describing is one where the GFC continues operating with the VFR GPS from the G3X after the GTN GPS fails. My AFMS doesn’t address this directly.

As I understand it, you can even use an Aera 760 as a position source for the GFC 500, but I would have to assume that it would still revert to heading mode when the GTN GPS dies. 

[PT20J]

In my installation (G3X/G5/GFC 500/ GTN 650Xi) either the G3X or G5 flight director will drive the GFC 500 and both have RS-232 connections to the GTN. If the GTN fails, I can switch the G3X Navigator from external to internal and use the G3X VFR GPS to navigate and provide a GPS source for the autopilot. 

[LANCECASPER]

9 hours ago, toto said:

Maybe. The scenario @PT20J is describing is one where the GFC continues operating with the VFR GPS from the G3X after the GTN GPS fails. My AFMS doesn’t address this directly.

As I understand it, you can even use an Aera 760 as a position source for the GFC 500, but I would have to assume that it would still revert to heading mode when the GTN GPS dies. 

If GPS testing, or jamming or interference is going on in that area, it won't matter how many GPS units you have, you won't be flying a coupled ILS approach with a GFC500. The problem will affect them all.

If the primary box just fails then the backup box should allow you to fly a coupled GPS or coupled ILS approach.

[PT20J]

I tried to design my installation to protect against single point failures. Failure of the GPS constellation is a concern because where I live in the Pacific NW, the MON network appears to me to be insufficient if there is really bad weather. But, the risk seems relatively small and it's something I cannot control. If I can get to an airport with a working ILS, having the ability to couple would be nice, but not critical.

[jetdriven]

This also underscore the value of having a separate standalone VHF navigator for times like this. In fact, I thought it was required in the STC to have either a second GPS or a separate standalone VHF navigator for IFR installations of GTN navigators. 

[PT20J]

1 hour ago, jetdriven said:

This also underscore the value of having a separate standalone VHF navigator for times like this. In fact, I thought it was required in the STC to have either a second GPS or a separate standalone VHF navigator for IFR installations of GTN navigators. 

Excellent point. It’s not required for SE piston aircraft 6000 lb. or less, and the second navigator can be a GPS, but prudence would seem to demand a second navigator. Since my G3X has an internal GPS, I installed a GNC 255 for #2.

[toto]

2 hours ago, PT20J said:

In my installation (G3X/G5/GFC 500/ GTN 650Xi) either the G3X or G5 flight director will drive the GFC 500 and both have RS-232 connections to the GTN. If the GTN fails, I can switch the G3X Navigator from external to internal and use the G3X VFR GPS to navigate and provide a GPS source for the autopilot. 

Do you know what the GPS position is actually used for when you’re flying an ILS? Everything I’ve seen from Garmin is vague on this. 

[PT20J]

37 minutes ago, toto said:

Do you know what the GPS position is actually used for when you’re flying an ILS? Everything I’ve seen from Garmin is vague on this. 

Garmin vague? How unusual . I don't know but my best guess is that they use it to smooth out variations in the localizer and/or glideslope.

What is interesting is that the first line of the pertinent section of the AFMS says, "This procedure applies only if the optional GPS navigator is installed:"

According to the install manual, if there is no GPS navigator but a VHF Nav Radio is interfaced through a GAD 29, then NAV and APR modes are available.

So if you never install a GPS, VHF approaches work, but if you install a GPS they don't unless the GPS works.

[Pinecone]

On 7/5/2024 at 4:05 PM, PT20J said:

Excellent point. It’s not required for SE piston aircraft 6000 lb. or less, and the second navigator can be a GPS, but prudence would seem to demand a second navigator. Since my G3X has an internal GPS, I installed a GNC 255 for #2.

That is interesting.

I have seen people doing a single GTN with a comm only #2.  And it seems that is NOT legal under the STC.

[jetdriven]

its legal for SE pistons under 6000lb.  I wouldnt do that. but its legal.  I have a friend with an inop NAV2. IO brought this up and he said he has an iPad, so hes covered.

[PT20J]

I keep the iPad on the yoke with ships power, but I would not rely on it to replace any certified equipment. That said I have found ForeFlight/iPad better than the panel mount equipment in a number of instances:

1. Both ForeFlight and ADS-B use tfr.faa.gov as the TFR source. However, this site does not have the "stadium" TFRs associated with major sporting events and ForeFlight uses other sources to depict these. Also, Garmin has had issues displaying all TFRs. A few months ago it issued a fix for a bug where a TFR lasting more than one day was depicted on the first day only. Recently, when Biden visited Seattle, the GTN depicted the VIP TFR but the G3X did not.

2. ForeFlight allows setting the transparency of overlays but the G3X does not, so if I have radar or terrain selected on the G3X, map features below are obliterated.

3. The GNSS receiver in the iPad receives position from Galileo, GLONAS, QZSS, BEIDOU as well as GPS. Maybe something will work 

[Aerodon]

On 7/3/2024 at 9:05 PM, PT20J said:

Garmin directly copied the KFC/KAP servo installation. In fact some dealers cut cost by reusing the BK brackets when replacing a KAP/KFC with a GFC. Garmin did have some mechanical issues with the GFC 500 servos, but that seems to be behind them and they have an offer out to replace all the potentially bad ones in the field for free including an installation labor allowance even if they are operating well. The GFC 500 FD uses a combination of attitude and rate based inputs for controlling the autopilot. For some reason, this doesn't work well in some airframes. It's not just Mooney: Cirrus and Bonanzas have had some pitch issues also. Garmin has issued alternate gain settings for J/K and presumably will issue them for other models as well which seems to fix the problem by dialing back the rate based component in the control loop.

Although, Garmin's communication with customers often leaves much to be desired, it's clear that Garmin has  continuously improved it's products and fixes problems that occur. My biggest concern with B-K is that I just don't see that Honeywell has nearly that level of commitment.

I was looking at pictures of the parts, as well as the Garmin GFC500 addendum for the Mooney installation.  The install manual allows you to reuse the aileron hardware except the mounting plate for the servo.  It makes no mention of the pitch and servo installation.

But it does look like the installation is similar.  The pushrod 'end clamps' look the same.  I'm not sure if the side brackets for the pitch and yaw servo are the same?  Some parts of the pitch & trim mounting look the same.

It does not take long to take out the KFC150.  And once everything is open, it seems like quite an easy installation.  I did a C172 and access to the rear fuselage is tedious to say the least.  The M20K looks a whole lot easier.

Aerodon

 

 

 

 

 

 

 

[0TreeLemur]

On 7/1/2024 at 9:05 PM, BlueSky247 said:

I am looking at an early J with a wing leveller. Are there any reasonable options for new equipment short of writing a big check on brand G? Something with at least course and altitude options?

You seek new equipment, but I did the same investigation and found that there presently isn't a real good non-Garmin solution in existence.   Like you, I didn't want to spend the > $50k on a whole panel upgrade.

One alternative solution is to buy a complete working B-K autopilot that someone else removes from their Mooney as part of a big-G upgrade and have it installed in your Mooney.  I have KFC-150 in my J.  I had the A/P computer (KC-192) IRAN'd by @Jake@BevanAviation .  Since April I've flown over 60 hours and it works flawlessly.   After flying 500 hours behind a Brittain system (Accutrak II, Accuflite, and PC-AH/Dynertial) in my C, I love the KFC-150.  It flies RNAV approaches like its on rails including glide slope.

Advantages: spare parts are relatively cheap and plentiful.   Jake has intimate knowledge of these systems with quick turn around.  They couple to Aspen PFDs.

Disadvantages: they require analog inputs, which means either BK analog attitude indicator or digital to analog converters between the Aspen and autopilot.  It's not the hot new thing so unlikely to add value to your Mooney.

If you know a shop doing upgrades you might be able to work out an installation deal in advance.

[BlueSky247]

@0TreeLemur Love it! Thank you Sir. I will look into that. Also - I see we are "neighbors". Would love to meet for a $100 hamburger sometime after I get mine home.

[jetdriven]

KFC is pretty complicated system and I don’t think anybody in the past 20 years has installed one of those things. We removed the pitch servo on a KFC150 to get it repaired and the thing has a 9-wire connector to it. And then it cost us 1000 bucks for them to replace a blown transistor inside of it.  I wouldn’t remove a working system but you’re not going to find someone willing to install a used system.  

[PT20J]

Buying a complete used KFC150 might have some issues. First, how do you know you have every little bit and piece? It’s common to find the servos and computer used, but there are lots of special mounting bits. Second, as Byron said, you’ve got to find someone willing to install it. Most shops wouldn’t touch it. What if they spend a couple of hundred hours installing it and it doesn’t work right? I know a guy that bought a used Aspen and a GNS 430 cheap at Oshkosh and still can’t find a shop willing to install it.

[0TreeLemur]

19 minutes ago, PT20J said:

Buying a complete used KFC150 might have some issues. First, how do you know you have every little bit and piece? It’s common to find the servos and computer used, but there are lots of special mounting bits. Second, as Byron said, you’ve got to find someone willing to install it. Most shops wouldn’t touch it. What if they spend a couple of hundred hours installing it and it doesn’t work right? I know a guy that bought a used Aspen and a GNS 430 cheap at Oshkosh and still can’t find a shop willing to install it.

If @BlueSky247 can identify a shop that has experience with the B-K equipment and is doing a big-G upgrade of a KFC-150 system, it could work.   Better yet if he has a friend in the business.   There are always removed systems for sale here and there in varying degrees of completeness.   I have two each spare servos for my KFC-150 system.   I bought three here on MS for $750 total from a member who did the big-G upgrade.  One set came with all the mounting hardware for the servos in the tail.   The only thing I'm missing is the aileron servo mounting hardware, which I don't need anyway.

The KC-192 flight computers are easy to buy for 28V systems, but more difficult to find for 14V aircraft.   Maybe someone here on MS is removing a system and can help him out?  I will swear by @Jake@BevanAviation's ability to keep this old stuff working well.   The KC-192 I sent him had multiple faults which he repaired for less than 1 AMU!

[PT20J]

I didn’t say it was impossible. But I would want a shop signed  up before I spent any money on equipment, and I would want a complete installation bill of materials so I was sure I had everything as I started accumulating parts. 

[Aerodon]

I have a complete KFC150 system removed from a 28V airplane.  I see the serves are labeled 14/28V so may be compatible.  The computer is 28V, you may be able to trade for a 14V one.

The harness is still intact with connectors on both ends.  The aileron wiring had a splice in it, so I cut it there rather and cut the connect off.  It was feasible to remove intact, so it will be feasible to install again.  

I have my GFC500 installation kit, and will have the complete aileron servo installation kit leftover. You will need to make sure you have the correct fuselage bulkhead behind the avionics tray to install the trim servo.  And that attaches to the pitch servo tray.  I am removing the two son alerts from the roof panel.  And I will be removing the valuable trim switch and PTC etc from the control column.

Installation manuals for the system are available, but I think you will be on your own for installation of the brackets.  And I think you will be up against a brick wall if you need to get a permission letter to use the BK STC.  You will need to install a KI256 attitude indicator and a KEA130A altimeter.

I think it is technically feasible.

But, just like you can't take a steak to a restaurant and ask them to cook it, anyone with the ability to install an autopilot would rather be selling you new hardware and spending the same or less time installing.

 

aerodon

 

 

 

 

 

 

 

[LANCECASPER]

6 hours ago, 0TreeLemur said:

You seek new equipment, but I did the same investigation and found that there presently isn't a real good non-Garmin solution in existence.   Like you, I didn't want to spend the > $50k on a whole panel upgrade.

One alternative solution is to buy a complete working B-K autopilot that someone else removes from their Mooney as part of a big-G upgrade and have it installed in your Mooney.  I have KFC-150 in my J.  I had the A/P computer (KC-192) IRAN'd by @Jake@BevanAviation .  Since April I've flown over 60 hours and it works flawlessly.   After flying 500 hours behind a Brittain system (Accutrak II, Accuflite, and PC-AH/Dynertial) in my C, I love the KFC-150.  It flies RNAV approaches like its on rails including glide slope.

Advantages: spare parts are relatively cheap and plentiful.   Jake has intimate knowledge of these systems with quick turn around.  They couple to Aspen PFDs.

Disadvantages: they require analog inputs, which means either BK analog attitude indicator or digital to analog converters between the Aspen and autopilot.  It's not the hot new thing so unlikely to add value to your Mooney.

If you know a shop doing upgrades you might be able to work out an installation deal in advance.

Just to verify - you didn't buy a used KFC-150 and install it in your airplane? You bought the airplane with the KFC-150 in it and had the KC-192 repaired, right? 

[Pinecone]

If anyone is interested in a 28V KAP-150, with altitude preselect, that was just taken out of my 252, contact me.

AP works great.  The KAS-297 has some issues when it is hot, like from sitting on the ramp in the sun.  I suspect some capacitors need replacing.

I have the brackets also.

[0TreeLemur]

On 7/7/2024 at 6:39 PM, LANCECASPER said:

Just to verify - you didn't buy a used KFC-150 and install it in your airplane? You bought the airplane with the KFC-150 in it and had the KC-192 repaired, right? 

That is correct.  The KFC-150 autopilot that came in my airplane was intermittent.  I took it too a shop for troubleshooting, and it turns out that the KC-192 installed was an early prototype unit.  Its firmware was very aggressive in altitude hold (+/- 20 ft!) and would almost make me throw up in moderate to severe turbulence.   Now I'm not prone to airsickness.  I've only ever puked in the air twice- once when I got sick from a virus, and the other time on the NASA Vomit Comet.  Jake suggested to me that I find a non-prototype unit with maximum mods and a P/N ending in -03 (discrete components, not surface mount soldered) which I did.   It had numerous discrepancies that he repaired.   I swapped out the computer, and now have a much better autopilot that doesn't try to make me puke.

I was just suggesting to @BlueSky247 that installing the KFC-150 was an option with the provisos already stated.

The 28 V KC-192's are much more common than the 14V models.   Ebay has several 28V KC-192's listed for 2AMUs.  The one or two 14V units listed are BIN for ~5 AMUs.  I lucked out and jumped on one with a P/N ending in -03 that came with all three servos for 3AMUs.  Deals can be had but are infrequent.