Replacing KI256 and KI525 combo with GI275's - Any Experiences?

[Fly_M20R]

On 8/13/2020 at 11:19 AM, FlyingScot said:

Greetings - I hope everyone is well and healthy - 

I am contemplating replacing my KI256/KI525A combo with GI275's (a GI275 ADAHRS+AP and a GI275 Base HSI).  I would also add a third 275 ( GI275 + ADAHRS) to act as an additional functional display, but could also be used as a failover from the primary AI GI275 (I know the HSI will do this, but this way, you don't compromise the HSI by cluttering it in an emergency, and can retain AP functionality in the failover).

I have a low-time 02 with the KFC225 and an upgraded stack including 750&650 Nav's. It seems like this is a good solution to eliminating the Vac system, digital-izing the primaries, and integrating with the rest of the Garmin stuff in the panel, w/o taking the full bite needed to install a G500Txi - that option is at least twice the price and also starts to move the amount I have put into the plane well past what I think it's reasonable to expect to get out of it - 

I love the aircraft, really love it, but think someday I will want to move into a turbo, so I can't yet justify investing like it's my forever plane.

Anyone have any experience with this type of replacement or with the GI275's in general? I did a search for this before posting, but didn't see much in the way of a discussion on this - 

Thanks in advance for any feedback/insights - Bob

 

Hi Bob,

I have taken "the leap" and my plane is already in the shop having two KI-275's installed as a replacement for the full six-pack. The top one is an ADAHRS+AP replacing my KI256 that has started to fail. The bottom one is an ADAHRS unit that will be a Standby ADI also configured as an MFD so that it can display the multitude of pages that an MFD can, including HSI, HSI MAP, etc... If it were a standby ADI configured as an HSI it would only be able to display a limited number of pages. Either way the second one would be the same cost for the hardware because it is ADAHRS. I have a GNS530W and a KFC150 that will be communicating without any issues with both GI275's. My KX155 won't be able to have its CDI displayed on the second 275 because it is a Standy ADI. It could if it were an independent HSI. Therefore I need to keep the KX155's CDI display. I also have a WX-1000 and it cannot be displayed on the 275's.

If I were you I would use the third 275 you want to purchase as an EIS unless you already have some graphical engine monitor you really like. No need to use the third 275 as an MFD/HSI  since you have great situational awareness with the dual GTN's and it would be extremely low probability for the primary ADI and standby ADI to both fail. You would still need some attitude and airspeed source in that case. If you got struck by lightning you might lose most if not all electronics. Hopefully you are not doing "hurricane hunting" with your Ovation... 

Why two GI-275's and not dual G5's? Because the G5's do not fully "talk" with the KFC-150. Even with a GAD they will not provide attitude info nor will they display a flight director. I would have had to have kept the KI256 which would have had to get overhauled or replaced in some way. More $$$.

I also chose not to upgrade to a full 10.6 inch landscape display because of the additional $$ that I did not want to spend at this time. Options were a G3X with a standby GI275 ADAHRS+AP so that the GI275 could fully talk with the KFC150. The G3X will not provide attitude info to the KFC150. It will only talk with Garmin equipment. Will also not talk with the KX155. It would have been at least $6,000 more for the install plus the cost of cutting a new panel which will run around $2,900. 

A G500 Txi would certainly talk to many other brands of NAV's as well as autopilots including the KFC150. I could have used a cheaper G5 as standby in this case. Even so, the cost would have been at least $11,000 more plus the $2,900 for cutting new panel, again more than I want to spend.

I discarded Dynon because it only talks to their autopilots and last time I looked they did not have the M20R in their AML for autopilots, only for their HDX. Since my KFC150 is working well there is no need to change it. If it were to fail or a servo need expensive overhaul/replacement I would then upgrade to a garmin GFC500. 

What seemed a nice alternative in terms of cost because of a significant discount promotion was a Bendix-King AeroVue Touch that is a 10.6" PFD/MFD and an AeroCruze 230 which is the digital autopilot replacement for the KFC150 and it would use the current servos and also provide them with a 2 yr extended warranty. The cost of that install would have been similar to that of a G500 Txi and getting a free autopilot computer. However, after some research I found out that in BK's usual modus operandi the AeroVue was not communicating with either the KFC150 or the AeroCruze 230. It would come in the next software upgrade that would also require certification. At the speed that BK does their stuff it could be 6 months at a minimum and most likely 1+ years for that to happen. In addition, who knows if they use the same hardware and software for their Attitude display as the infamous KI-300. As such it was a no-go option.

Garmin has superb software that interprets their ADAHRS  info because they pass a "torture test" with flying colors. It requires disconnecting the pitot source and flying three shallow (~ 20 deg) turns. Passing means having the Attitude Indicator stay in the turn. It will fail if it straightens out to level during any of these turns. Sandia fails all the time. Apparently Aspen passes. Not sure about Dynon.

Garmin may cost a bit more but it is superb quality.

I have started a series of videos about the install. Part 1 is the decision making process. Part 2 is after removing the instruments and the panel. Part 3 will be with new wiring in place and getting the GI275's in the panel. Part 4 will be first flight. I am providing links to my first and second videos below.

Part 1: 

 

[Fly_M20R]

This is part 2 of the videos:

 

[Fly_M20R]

On 9/2/2020 at 9:36 AM, Greg_D said:

Does anyone else besides me wish that Garmin had put the control knobs on the 275s on the bottom right hand corner of the instrument, instead of the left?  I usually fly with my left hand and use my right hand for the avionics and engine controls, etc.  It just seems like it would require less reaching around the yoke if they were placed on the right side.

Absolutely agree with you Greg_D!!! I have mine in the shop for dual 275 install and can't figure out who missed that basic ergonomic issue at Garmin. Even left handed pilots have to use their right hand for the radio stack, throttle, etc while keeping left on yoke. I doubt that they swap hands to reach the left sided knobs on the 275's. Maybe they thought that most pilots have gotten used to moving across the HSI to turn the course (OBS) knob and so would find it similar with the 275's. Even so, turning the OBS know happens much less frequently than turning the heading bug.

I wonder if in some near future software upgrade they can rotate the display 90 deg clockwise allowing the whole unit to be turned 90 deg CCW to end up with the knob on the lower right. ????

[FlyingScot]

 

2 hours ago, Fly_M20R said:

 

Hi Bob,

I have taken "the leap" and my plane is already in the shop having two KI-275's installed as a replacement for the full six-pack. ...

If I were you I would use the third 275 you want to purchase as an EIS unless you already have some graphical engine monitor you really like. No need to use the third 275 as an MFD/HSI  since you have great situational awareness with the dual GTN's and it would be extremely low probability for the primary ADI and standby ADI to both fail. You would still need some attitude and airspeed source in that case. If you got struck by lightning you might lose most if not all electronics. Hopefully you are not doing "hurricane hunting" with your Ovation... 

I have started a series of videos about the install...

Thanks for the great posts ~ you and I are in parallel, my O2 went under the knife last week. I went through a similar evaluation, and came up with pretty much the same conclusions.

The reason I went with the third 275 as an MFD is a little different – in my install, AI failover will go to the MFD, not the HSI. This allows you have a fully functional and independent AI plus a separate HSI in the event that there’s a primary AI failure, rather than using a combined instrument. With this arrangement the HSI can be just a base unit;  it does not need AHARS. The two full blown boxes are the AI and MFD. The MFD is going where my old backup electric AI was in my panel. 

i’m happy with my engine monitor, all of that may change if my Moritz gauges fail, however. Making the third an MFD will allow for simultaneous display of Sirius and ADS-B weather ~ I find myself doing a lot of flipping back-and-forth between these two on the 750 a lot in the soup when navigating around the cells in the southeast. I hope This works to alleviate some of that. Dodging convective cells is something I know you’re very familiar with.

And having lived through at least a dozen hurricanes on the ground, I have no desire to chase one in the air !

I look forward to your next installments and I will post pics when I get some.

I agree with you on one other thing – when they tear into a panel, the result is a frightening sight.

Cheers – Bob

[Fly_M20R]

2 hours ago, FlyingScot said:

 

Thanks for the great posts ~ you and I are in parallel, my O2 went under the knife last week. I went through a similar evaluation, and came up with pretty much the same conclusions.

The reason I went with the third 275 as an MFD is a little different – in my install, AI failover will go to the MFD, not the HSI. This allows you have a fully functional and independent AI plus a separate HSI in the event that there’s a primary AI failure, rather than using a combined instrument. With this arrangement the HSI can be just a base unit;  it does not need AHARS. The two full blown boxes are the AI and MFD. The MFD is going where my old backup electric AI was in my panel. 

i’m happy with my engine monitor, all of that may change if my Moritz gauges fail, however. Making the third an MFD will allow for simultaneous display of Sirius and ADS-B weather ~ I find myself doing a lot of flipping back-and-forth between these two on the 750 a lot in the soup when navigating around the cells in the southeast. I hope This works to alleviate some of that. Dodging convective cells is something I know you’re very familiar with.

And having lived through at least a dozen hurricanes on the ground, I have no desire to chase one in the air !

I look forward to your next installments and I will post pics when I get some.

I agree with you on one other thing – when they tear into a panel, the result is a frightening sight.

Cheers – Bob

Sounds like your tank reached its 15 years end of life! Mine did so last year. I was able to save a bit of $$ by taking it out and putting it in myself. An A&P friend signed it off after verifying that there were no leaks. I just helped a friend with a Bravo that has a G1000 in it put his back in. I will tell you that all the G1000 radios in the back of his plane make it almost impossible to maneuver the tank. Had to remove one radio which was easy, but ughhhhh!!!!

You have obviously thought out your installation very carefully. The upgrade you choose HAS to work for you in how you fly the plane. You obviously have quite a few hours in the soup as well as dodging TS's so what you describe is perfect. No need to be changing screens if you have enough of them to display all the stuff you need and want to look at for a safe flight.

What kind of engine monitor do you have? I really like my G4 for the Exhaust Valve Analysis and Vibration Analysis as well as its sample rate and how it displays how many degrees each EGT is away from peak. I just don't like its current position in the lower left quadrant!!

Looking forward for updates in your installation as well as reports of your flight experience with it!

Happy flying soon!!  "Time flies"... 

[carusoam]

Great details Gents!
 

Best regards,

-a-

[FlyingScot]

SITREP: Install is functionally complete - one remaining config issue which is turning out to be a bit of a bear.

Recap - Replacing my KI256/KI525A combo with GI275's (a GI275 ADAHRS+AP and a GI275 Base HSI) plus a third GI275 + ADAHRS an additional functional display, as well as a failover from the primary AI GI275. Interfaced with the existing KFC225 and an upgraded stack including 750&650 Nav's. Removed the entire Vacuum system (yay!). Panel is beautiful, and the avionics shop has done their usual great work. 

It's actually turned out to be a pretty cool setup. Everything now talks to everything - with one exception.

The one issue remaining is the HDG and NAV signals from the GI275 to the KFC  The lines are live in the diagnostic mode, but inactive in normal mode. Apparently a software config issue, and Garmin is working on it. Will post the resolution when it is found, b/c this is not an unusual configuration. Interesting problem; the avionics shop is a bit frustrated - hopefully to be resolved in the next day or so.  

Cheers - Bob

[P.S.> One fine-print surprise to be aware of: the 275MFD will not display weather from the GD69A - ONLY the GD69A SXM. They are plug compatible, so a upgrade ($$) will fix that problem - but weather displays just fine on the 750 in any event This is not clear from the sales literature, but is in the fine print of the install manual.] 

[FlyingScot]

Well it’s in - all bugs fixed. First impressions - I like it - a lot. Amazing level of integration. With everything talking to everything else, the set up options are pretty mesmerizing. KFC 225 integration is very good — approach capture and track precision seem better.

Test flights this weekend, some more comments to come. Lots of subtleties in configuration and in upgrading databases. 

+ No Vac!

 

[Fly_M20R]

On 10/4/2020 at 11:28 AM, FlyingScot said:

SITREP: Install is functionally complete - one remaining config issue which is turning out to be a bit of a bear.

Recap - Replacing my KI256/KI525A combo with GI275's (a GI275 ADAHRS+AP and a GI275 Base HSI) plus a third GI275 + ADAHRS an additional functional display, as well as a failover from the primary AI GI275. Interfaced with the existing KFC225 and an upgraded stack including 750&650 Nav's. Removed the entire Vacuum system (yay!). Panel is beautiful, and the avionics shop has done their usual great work. 

It's actually turned out to be a pretty cool setup. Everything now talks to everything - with one exception.

The one issue remaining is the HDG and NAV signals from the GI275 to the KFC  The lines are live in the diagnostic mode, but inactive in normal mode. Apparently a software config issue, and Garmin is working on it. Will post the resolution when it is found, b/c this is not an unusual configuration. Interesting problem; the avionics shop is a bit frustrated - hopefully to be resolved in the next day or so.  

Cheers - Bob

[P.S.> One fine-print surprise to be aware of: the 275MFD will not display weather from the GD69A - ONLY the GD69A SXM. They are plug compatible, so a upgrade ($$) will fix that problem - but weather displays just fine on the 750 in any event This is not clear from the sales literature, but is in the fine print of the install manual.] 

 

Hi Bob,

Very nice setup! Hopefully you got the communication between GI275 and the KFC solved. There are quite a few configuration intricacies and wiring subtleties involved with the 275’s.

I had the same surprise when I found out that my current GDL69A will not talk with the 275’s, even with a software upgrade. It needs as GDL69A SXM representing extra unplanned $$ for install. I have the wiring in place - a high speed data bus line - from the GDL to 275 for eventual future upgrade. As of now it displays just fine on y 530W.

I am not sure why you chose to keep the rest of the six-pack since per the STC your install allow to replace the whole six-pack. Yes, you have redundancy with the analog gauges but it also introduces points of failure with some leakage possibilities in the pitot-static system. I got rid of the six-pack and don’t get distracted by the analog gauges. Obviously it is personal preference.

I’ll be posting videos of my first flight(s) soon. I already have done a couple of RNAV approaches and also did a night flight. 

[Fly_M20R]

This is a picture of my first approach. Notice the deviation indicators on both the AI and HSI. Also note the minimums bug coming up on the altitude tape. It’s set at 462 ft. Synthetic vision is a significant plus!! Still need two cover plates for the empty holes....

Edited October 18, 2020 by Fly_M20R
Misspelling

[carusoam]

Way cool...

You get the runway and the green target lined up...

Your 275’s version of attaboy, keep coming!   

Great pic.

Go O1!

Best regards,

-a-

[Fly_M20R]

6 minutes ago, carusoam said:

Way cool...

You get the runway and the green target lined up...

Your 275’s version of attaboy, keep coming!   

Great pic.

Go O1!

Best regards,

-a-

 

Thanks!

Yep, line up the “pipper” with the approach end of the runway and keep it there. 

Next upgrade will be a GTN750 along with a GFC500 and possibly a GTN650 as well as a Garmin EIS.

Go O1!!!

[FlyingScot]

10 hours ago, Fly_M20R said:

 

Hi Bob,

Very nice setup! Hopefully you got the communication between GI275 and the KFC solved. There are quite a few configuration intricacies and wiring subtleties involved with the 275’s.

I had the same surprise when I found out that my current GDL69A will not talk with the 275’s, even with a software upgrade. It needs as GDL69A SXM representing extra unplanned $$ for install. I have the wiring in place - a high speed data bus line - from the GDL to 275 for eventual future upgrade. As of now it displays just fine on y 530W.

I am not sure why you chose to keep the rest of the six-pack since per the STC your install allow to replace the whole six-pack. Yes, you have redundancy with the analog gauges but it also introduces points of failure with some leakage possibilities in the pitot-static system. I got rid of the six-pack and don’t get distracted by the analog gauges. Obviously it is personal preference.

I’ll be posting videos of my first flight(s) soon. I already have done a couple of RNAV approaches and also did a night flight. 

I now have about 15 hrs on the panel, and a bunch of approaches, three in actual. 

I really like this setup. Flies beautifully, with no issues. Integration across all elements is impressive. What I have learned so far:

- Incredible flexibility. Configuration options are dazzling, and it took a while to get into a rhythm of how to set everything up enroute and in transition to the approach segment. I do like the SynVis, by the way, but I do a lot of flying on the mountains. In the plains it would not be worth it. 

- The terrain DB takes a bit of time to verify, so I now turn on the Master (which powers-up the ADI and MFD) and wait until the terrain DB verification finishes before turning on the Avionics Master.  This avoids a terrain config error. 

- All of the comm and configuration issues with the KFC 225 are resolved, and the GPSS tracks much more accurately than with the KI256/KI525A combo. Plus I like the ability to dial in headings/CDIs digitally.  

--> INTERESTING FINDING...

The 275 HSI and MFD CDI sources can be switched to any NAV or GPS in the GTN 750/650 stack (i.e. GPS1/LOC1/GPS2/LOC2), all sources appear to be active at all times, and the KFC225 nav source is determined by what source is selected/displayed on the HSI, NOT the CDI setting on the 750 or 650. For example, if I am on the final approach segment of a RNAV GPS LPV approach that has an overlapping ILS and if I also tune the 750 to the appropriate localizer frequency, the 750 outputs both the GPS track and GS and LOC/GS signals at all times (I know this b/c I can display, GPS1 on the HSI and LOC1 simultaneously on the MFD). Same for GPS enroute and offtrack VOR sensing. 

It appears that the CDI on the 750 can be left on GPS, and for an ILS approach switching over to the ILS is done simply by switching the displayed source on the HSI before the FAF (before selecting APR on the 225); it does not appear to need to be necessary to switch the 750 CDI to VLOC from GPS. So it isn't clear what purpose the CDI button on the 750 serves, since changing it has no effect on the state of the HSI or by extension the guidance being sent to the KFC225.

There is the matter of manually switching the 750 output into APR mode for GPS approaches, but that seems to work as before. I spoke with Garmin tech support on this, and they said this seemed right, but they also said the CDI state on the 750 should be changed as appropriate anyway without being able to offer a reason why. Perhaps a future software upgrade will address this in some way.

More to come, and I will be happy to answer any questions from anyone contemplating this upgrade.

Cheers - Bob

P.S.> @Fly_M20R I know I could have eliminated the steam gauges but I did not deliberately b/c I have been in a dramatic unusual attitude in IMC (AP failure put the plane rapidly into a climbing steep turn) and I find it is much easier to confirm what is happening in that kind of situation from moving and pointing needles than from reading and interpreting a tape.  Plus the KFC225 still takes its altitude data from the KEA130A (the GI275 KFC225 support does not include altitude), so that had to stay in any event.

The instrument I am going to replace next is the GI-106B which is wired to the 650. I am eventually going to swap it out for the EIS and eliminate the Moritz cluster. I thought having a alternate VOR head would be useful, but with the flexibility of the MFD, it isn't at all. In fact, the 650 senses the 275s, and disables the bearing select on the 106B, deferring to the bearing select in the MFD or HSI when LOC2 is selected. 

[Greg_D]

9 hours ago, Fly_M20R said:

This is a picture of my first approach. Notice the deviation indicators on both the AI and HSI. Also note the minimums bug coming up on the altitude tape. It’s set at 462 ft. Synthetic vision is a significant plus!! Still need two cover plates for the empty holes....

Can't wait to see the videos!
 

[Fly_M20R]

On 10/18/2020 at 6:41 PM, FlyingScot said:

I now have about 15 hrs on the panel, and a bunch of approaches, three in actual. 

I really like this setup. Flies beautifully, with no issues. Integration across all elements is impressive. What I have learned so far:

- Incredible flexibility. Configuration options are dazzling, and it took a while to get into a rhythm of how to set everything up enroute and in transition to the approach segment. I do like the SynVis, by the way, but I do a lot of flying on the mountains. In the plains it would not be worth it. 

- The terrain DB takes a bit of time to verify, so I now turn on the Master (which powers-up the ADI and MFD) and wait until the terrain DB verification finishes before turning on the Avionics Master.  This avoids a terrain config error. 

- All of the comm and configuration issues with the KFC 225 are resolved, and the GPSS tracks much more accurately than with the KI256/KI525A combo. Plus I like the ability to dial in headings/CDIs digitally.  

--> INTERESTING FINDING...

The 275 HSI and MFD CDI sources can be switched to any NAV or GPS in the GTN 750/650 stack (i.e. GPS1/LOC1/GPS2/LOC2), all sources appear to be active at all times, and the KFC225 nav source is determined by what source is selected/displayed on the HSI, NOT the CDI setting on the 750 or 650. For example, if I am on the final approach segment of a RNAV GPS LPV approach that has an overlapping ILS and if I also tune the 750 to the appropriate localizer frequency, the 750 outputs both the GPS track and GS and LOC/GS signals at all times (I know this b/c I can display, GPS1 on the HSI and LOC1 simultaneously on the MFD). Same for GPS enroute and offtrack VOR sensing. 

It appears that the CDI on the 750 can be left on GPS, and for an ILS approach switching over to the ILS is done simply by switching the displayed source on the HSI before the FAF (before selecting APR on the 225); it does not appear to need to be necessary to switch the 750 CDI to VLOC from GPS. So it isn't clear what purpose the CDI button on the 750 serves, since changing it has no effect on the state of the HSI or by extension the guidance being sent to the KFC225.

There is the matter of manually switching the 750 output into APR mode for GPS approaches, but that seems to work as before. I spoke with Garmin tech support on this, and they said this seemed right, but they also said the CDI state on the 750 should be changed as appropriate anyway without being able to offer a reason why. Perhaps a future software upgrade will address this in some way.

More to come, and I will be happy to answer any questions from anyone contemplating this upgrade.

Cheers - Bob

P.S.> @Fly_M20R I know I could have eliminated the steam gauges but I did not deliberately b/c I have been in a dramatic unusual attitude in IMC (AP failure put the plane rapidly into a climbing steep turn) and I find it is much easier to confirm what is happening in that kind of situation from moving and pointing needles than from reading and interpreting a tape.  Plus the KFC225 still takes its altitude data from the KEA130A (the GI275 KFC225 support does not include altitude), so that had to stay in any event.

The instrument I am going to replace next is the GI-106B which is wired to the 650. I am eventually going to swap it out for the EIS and eliminate the Moritz cluster. I thought having a alternate VOR head would be useful, but with the flexibility of the MFD, it isn't at all. In fact, the 650 senses the 275s, and disables the bearing select on the 106B, deferring to the bearing select in the MFD or HSI when LOC2 is selected. 

 Hi Bob,

The configuration options are definitely "quite dazzling" as you say! It does take a while to get in the rhythm to figure out which ones and what processes to use in different phases of flight. Still working on it as well as focusing on what is displayed on the ADI and HSI pages during an approach so that can make best use of the info. My autopilot is still out for repair so have had to fly my actual IFR approaches manually which can stress the brain bandwidth a bit... 

Regarding your interesting finding about the CDI function, what my install shop and a call to Garmin told me is that the STC requires the CDI to be disabled on the GPS navigator (e.g 530W which I have, and others). Mine has been disabled and does not show any source above the CDI button. As you found out, the CDI function has been moved to the HSI (or standby ADI/MFD) and as you well noted the navigator(s) will send simultaneous GPS and LOC data over to the GI 275's. It is same logic as if you were using a G1000 where you really don't have a separate navigator box and you pick what to fly by and display on the HSI. That is the info that should be sent to the autopilot as well for tracking. I have not flown an ILS yet and have not seen how the navigator (530W, 750, etc) and GI275 combo work out automatically changing from GPS mode in vectors to final to LOC once inside the approach "gate". According to the manual you still have to set the navigator to automatically do the switch which apparently the GI275 senses and changes accordingly. Not sure what your experience may have been with this.

Regarding you encoding altimeter having to stay in since it is supposed to be the only source of baro-altitude for your KFC225, I believe that the GI275 does output baro-altitude because it does show up on my 530W in the TAS/density altitude calculation AUX page. Any change in barometric pressure will change the value in indicated altitude which matches the indicated altitude in the GI275 ADI. The 530W does not have a high speed data bus and so I am surprised that you can't tie the 225 to the 275 with baro-altitude. I only have a KFC150 without altitude preselect so my installation did not need that connection. It could be quite different for the 225. 

The GI275 EIS seems to be a really superb instrument and can be used as primary for all engine instruments. For me the only drawback is that it does not display BOTH EGT's and CHT's simultaneously. This could be an issue when trying to figure out an engine malfunction due to detonation, pre-ignition, plugged injector, or mag/sparkplug issue. You would have to switch back and forth between the CHT and EGT pages while handling the rest of the potential emergent issue. Unfortunately, it is the only one that fits in a standard 3 (plus fraction) inch hole AND replaces all the instruments and is reasonably priced. Can't have it all!

You do have an amazing panel!!! 

Regards,

Chris

 

[FlyingScot]

@Fly_M20R - Chris, an excellent description - 

On 10/20/2020 at 11:50 AM, Fly_M20R said:

Regarding your interesting finding about the CDI function, what my install shop and a call to Garmin told me is that the STC requires the CDI to be disabled on the GPS navigator (e.g 530W which I have, and others). Mine has been disabled and does not show any source above the CDI button. As you found out, the CDI function has been moved to the HSI (or standby ADI/MFD) and as you well noted the navigator(s) will send simultaneous GPS and LOC data over to the GI 275's.

 

Further investigation - this is absolutely correct - and it is now gone from my 750. I kept it on the 650, b/c it actually is needed to switch the mode of the GI-106B.

On 10/20/2020 at 11:50 AM, Fly_M20R said:

I have not flown an ILS yet and have not seen how the navigator (530W, 750, etc) and GI275 combo work out automatically changing from GPS mode in vectors to final to LOC once inside the approach "gate". According to the manual you still have to set the navigator to automatically do the switch which apparently the GI275 senses and changes accordingly. Not sure what your experience may have been with this.

This, it turns out, is a bit different for me. This is how I would like it to work, but in the case of the KFC225, when the mode change is asserted by the GTN750 via the GI275 (it does this via an analog line) the KFC automatically goes not to APR, but to ROL/PIT. This behavior is particular to the KFC225 and KAP140. The Garmin solution to the ambiguity (and potential danger, if it goes unnoticed) this creates is to force the pilot to switch modes  manually - but only for the KFC225 and the KAP150.

If you set this to AUTO - then the GTN will switch the mode automatically "in the box" somewhere, but there is no audible or other indication that the autopilot is no longer tracking the final course or GS (or Altitude for that matter).

 

I flew two full (RNAV and ILS, both with course reversal, etc) approaches today in VFR  conditions to test everything out. It's fantastic - I hope you are enjoying it as much as I am. 

I am assembling a wish-list for Garmin, though, and at the top of it is the ability to change ADI presentations (from basic to 3 in 1, to 4 in 1) from the user setup and not system config mode. I would love to display more data on the ADI than the one box permitted in 4 in 1 mode.

More to come - I look forward to your videos - Best - Bob

 

 

[Fly_M20R]

Well... I have had both units installed for around 4 weeks and have been getting through some configuration issues to make ny 530W, 275’s and KFC 150 work as expected. Final issue to resolve is that the 275 does not seem to recognize it is in an ILS/LOC and although the KFC will fly the LOC perfectly it will not track the GS. Instead, it will descend slowly and end up high with full scale deflection of the GS about 2/3 of the way from FAF to DA. I believe the shop has narrowed the issue down to one setting and will do a ground test on it today followed by me doing a test flight weather permitting.

It flies GPSS perfectly as well as an RNAV approach down to minimums.

Although the dual 275 setup is amazing in its features and gives me all the info I ever wanted I do have a couple of user friendly issues with the units:

• I do believe that the concentric buttons should be on the bottom right rather than the bottom left of the unit, or have two sets of buttons - one on bottom left and other on bottom right.
• The GPSS vs HDG mode selection is buried 3 levels deep in the menu. It should either be on the top level or have a screen area on which to toggle the selection. This is the most frequent complaint of 275 users and Garmin is very aware of it and plan to change it in next software update.
• Setting up minimums for an approach is two levels deep in the menu and I also believe should be at top level or a screen selection because it can get busy in IFR. The feature does work wonderfully!!

[Greg_D]

On 11/9/2020 at 7:52 AM, Fly_M20R said:

Well... I have had both units installed for around 4 weeks and have been getting through some configuration issues to make ny 530W, 275’s and KFC 150 work as expected. Final issue to resolve is that the 275 does not seem to recognize it is in an ILS/LOC and although the KFC will fly the LOC perfectly it will not track the GS. Instead, it will descend slowly and end up high with full scale deflection of the GS about 2/3 of the way from FAF to DA. I believe the shop has narrowed the issue down to one setting and will do a ground test on it today followed by me doing a test flight weather permitting.

It flies GPSS perfectly as well as an RNAV approach down to minimums.

Although the dual 275 setup is amazing in its features and gives me all the info I ever wanted I do have a couple of user friendly issues with the units:

• I do believe that the concentric buttons should be on the bottom right rather than the bottom left of the unit, or have two sets of buttons - one on bottom left and other on bottom right.
• The GPSS vs HDG mode selection is buried 3 levels deep in the menu. It should either be on the top level or have a screen area on which to toggle the selection. This is the most frequent complaint of 275 users and Garmin is very aware of it and plan to change it in next software update.
• Setting up minimums for an approach is two levels deep in the menu and I also believe should be at top level or a screen selection because it can get busy in IFR. The feature does work wonderfully!!

I enjoyed the YouTube video and I'm looking forward to seeing you video some approaches with your setup.  Since you have the KAP150, I'm guessing there is no altitude preselect.  Would you gain that capability if you switched to a GFC-500 down the road?  And for those of us with the KFC150 and a KAS297B for altitude preselect, would we be able to keep that capability with the GI275s?

[Fly_M20R]

16 hours ago, Greg_D said:

I enjoyed the YouTube video and I'm looking forward to seeing you video some approaches with your setup.  Since you have the KAP150, I'm guessing there is no altitude preselect.  Would you gain that capability if you switched to a GFC-500 down the road?  And for those of us with the KFC150 and a KAS297B for altitude preselect, would we be able to keep that capability with the GI275s?

Hi Greg_D

I actually have a KFC 150 but do not have altitude preselect.

To answer your questions as best as I can: Yes, you would have altitude pre-select with a GFC500 plus several other features. I also believe that the AP modes may be displayed on the 275.

I presume that you would still have altitude pre-select with your setup since it is separate from the GI 275. I say “presume” since I have not explored that issue.

I have a video on takeoffs using the flight director which works perfectly on the GI 275 whereas it was unreliable on the KI 256 for takeoffs. I will post the link in next message. May open a separate topic on it too.

[Fly_M20R]

Here is a video of takeoffs using the flight director from my KFC 150 on the GI 275. I did the first one during the day and the second at night taking off into a “Black Hole” over the ocean. Very stable compared to the FD on the previous vacuum driven KI 256

 

 

[Greg_D]

8 hours ago, Fly_M20R said:

Hi Greg_D

I actually have a KFC 150 but do not have altitude preselect.

To answer your questions as best as I can: Yes, you would have altitude pre-select with a GFC500 plus several other features. I also believe that the AP modes may be displayed on the 275.

I presume that you would still have altitude pre-select with your setup since it is separate from the GI 275. I say “presume” since I have not explored that issue.

I have a video on takeoffs using the flight director which works perfectly on the GI 275 whereas it was unreliable on the KI 256 for takeoffs. I will post the link in next message. May open a separate topic on it too.

Thanks for the update.  I'm not sure how I missed the KFC150 in your plane, vs the KAP150.  The flight director is in both the before and after videos!  I flew an Ovation with a KAP150 today that did have the altitude preselect.  I think I'd miss being able to select altitudes more than the flight director after seeing that setup in action. 

I'm wondering if there wasn't something wrong with your KI-256.  Mine moves a tiny bit going down the runway, but not like what you showed in your before video.

Anyway, thanks again for the excellent videos and analysis.

[Fly_M20R]

8 hours ago, Greg_D said:

Thanks for the update.  I'm not sure how I missed the KFC150 in your plane, vs the KAP150.  The flight director is in both the before and after videos!  I flew an Ovation with a KAP150 today that did have the altitude preselect.  I think I'd miss being able to select altitudes more than the flight director after seeing that setup in action. 

I'm wondering if there wasn't something wrong with your KI-256.  Mine moves a tiny bit going down the runway, but not like what you showed in your before video.

Anyway, thanks again for the excellent videos and analysis.

Hi Greg_D,

I had altitude pre-select in two previous Mooneys and it is a great feature for sure!! Fortunately the GI 275 has a visual warning 1000 ft prior to reaching the target altitude and aural+visual 200 feet prior to target. Better than nothing at all.

The runway from which I took off w the KI 256 has quite a few irregularities even if paved. It's at an airpark. The KI 256 did fail anout 7 months later though during run-up for a true IFR flight. Hence my 275 install.  

Thanks!

[flysamo]

6 hours ago, Fly_M20R said:

Hi Greg_D,

I had altitude pre-select in two previous Mooneys and it is a great feature for sure!! Fortunately the GI 275 has a visual warning 1000 ft prior to reaching the target altitude and aural+visual 200 feet prior to target. Better than nothing at all.

The runway from which I took off w the KI 256 has quite a few irregularities even if paved. It's at an airpark. The KI 256 did fail anout 7 months later though during run-up for a true IFR flight. Hence my 275 install.  

Thanks!

 

 

[flysamo]

IMG_0498[6902] - Copy (2).HEICagree with other comments, getting used to the new system and comfortable with the system takes learning and practice, IMG_0498[6902] - Copy (2).HEIC  the beauty is in the design, using G275's with GFC 500 and XI 750 is the way it work together. we now features we have wanted for a long time. Only time we have to touch the 275 is to set the baro. love alt. climb to and hold, descend function and the list goes on

[carusoam]

Great demonstration, F_M20R!

Thanks for sharing all the details.

Really nice to see the panel all back together too! 

Best regards,

-a-