Approaches with G 275s

[WDD]

Doing some planning, and thinking of putting in dual G 275 (besides getting rid of vacuum system, they will also be needed to drive new AP).

For those who have G 275s or even G5s, what is your experience with flying approaches compared to the mechanical old school CDI? Specifically, the glide slope?

As a guy who's odometer recently turned over the 60 mark (but hey, I'm getting discounts now at the Waffle House), and as a bi focal glasses guy, I do appreciate the simpler cross hair CDI type display.

Should I even consider adding a third G 275 as a dedicated CDI to mirror the glide slope information that would be shown on the G275 acting as the HSI?

Overthinking all of this? Sure, why not.

 

[RussR]

Are you just asking about the differences between a CDI and an HSI presentation?


You will find an HSI is a far better and easier to interpret presentation than a CDI. There's a reason that HSIs are the standard in any glass panel aircraft, and have been in anything bigger than a light twin for decades.

I typically find when training clients on avionics upgrades that it takes them about one approach to get comfortable with the localizer display part of an HSI. And just a few more to remember to look for the GS needle in a slightly different place. But after the first flight, no more concern about it. An HSI is very intuitive.

 

[WDD]

Thank you Russ - exactly the type of advice I was looking for. Appreciate it.

 

[TCABM]

Dual G5 guy here. Flying an approach, I primarily use the deviation indicators on the PFD as primary guidance and cross check with the G5 HSI. The diamonds circled below are green for ILS/LOC/VOR and magenta for GPS. If there’s no vertical guidance, you just get the lateral indicator.

Because we also have a KX155, for VOR/LOC/ILS, I’ll tune that up and send it to its mechanical CDI as a backup.

I hope that makes sense.

 

[asicer]

Subscribe to synthetic vision and put the FPM on the runway. Coupled with a GFC500, just match up the chevrons with the flight director.

 

[Llewtrah381]

I’ve had two 275s for a little over a year and have an old school indicator for my nav (for ILS). My old brain still has to remember the magenta diamond is the equivalent of the white bar on occasion but I get there.

I had very little time behind an HSI before this but definitely like it. At first I thought the “HSI map” page would be overkill but seeing the dotted track line and getting it to overlay the magenta line is nice. That said, I personally think the synthetic vision would be more of a feature than a benefit but I could be wrong on that too.

I highly recommend you do a good comparison of the 275 vs the G5. Although the 275 is physically smaller, it actually has a bigger image, sharper screen, and I think better features. I’m kinda surprised they still sell the G5s after the 275s rolled out. But again, I could be overlooking something.

BTW: I may be mistaken but I think there’s a 275 option that’ll let you scroll between HSI and CDI but I don’t think that model can be used as a backup for the 275 that’s a primary ADI for some reason.

 

[robin ardoin]

I had an HSI in the 182 prior to putting dual 275's/gfc500. I've only flown two approaches so far, LPV, and used the standard HSI presentation (only 3.5 hrs behind it and 6 landing). On one I just used the ADI and kept the 'diamonds' centered and hand flew it. On the other I just sipped coffee until DA then took over and landed....gotta love the GFC500 . Seriously though, the Flight Director and Command Bars are a game changer for this steam gauge only guy. So many references to where you are/need to be with this system including the cue given with SVT.

 

[midlifeflyer]

The use of a vertical tape rather than a horizontal line is standard in glass PFDs. Like everything else about glass, one needs to receive effective training and do it enough to get used to it. How long it takes depends on you. If you have a traditional CDI also, force yourself to use the glass. Cover the other one if you have to.

 

[chemgeek]

Dual G5s are easy to fly for LPV or ILS approaches. The AI has everything you need (horizontal and vertical CDI tapes), but I crosscheck with the HSI, which basically displays the same information, but the HSI gives a better graphical display of the wind correction angle being used. A cheap hack if flying with the GPS map display page visible is that if you put the magenta line vertical, that's your current reference heading. If the CDI tapes are centered, keep that line vertical and you will stay right on track. It took me very little time to acclimate to the G5 displays. It's a huge bonus to have all the flight information you need on the two central units in the scan. It took me longer to get used to the digital airspeed and altimeter tapes than the CDI tapes. The analog altimeter and airspeed dials are somehow easier to quickly assimilate than the numerical tapes.

 

[Clip4]

Doing some planning, and thinking of putting in dual G 275 (besides getting rid of vacuum system, they will also be needed to drive new AP).

For those who have G 275s or even G5s, what is your experience with flying approaches compared to the mechanical old school CDI? Specifically, the glide slope?

As a guy who's odometer recently turned over the 60 mark (but hey, I'm getting discounts now at the Waffle House), and as a bi focal glasses guy, I do appreciate the simpler cross hair CDI type display.

Should I even consider adding a third G 275 as a dedicated CDI to mirror the glide slope information that would be shown on the G275 acting as the HSI?

Overthinking all of this? Sure, why not.

View attachment 130269

The GI 275 comes with about 10 hours of synthetic vision preloaded as a trial. Once this time expires, if you wish to continue having Synthetic Vision enabled, there is a feature enablement that must be purchased through an authorized Garmin Dealer, or on the website Fly.Garmin.com.

 

[robin ardoin]

The GI 275 comes with about 10 hours of synthetic vision preloaded as a trial. Once this time expires, if you wish to continue having Synthetic Vision enabled, there is a feature enablement that must be purchased through an authorized Garmin Dealer, or on the website Fly.Garmin.com.

Yep...$500 retail. My installer gave me a discount to $400.

 

[Clip4]

Yep...$500 retail. My installer gave me a discount to $400.

Another Garmin / Boeing rip off scheme.

 

[ROBERT DAVISON]

The glideslope/path indicators on the G5 and 275s are adequate but really a bit small in my opinion. A flight director helps tremendously when following vertical guidance, so that the size of the primary vertical deviation indicator becomes less important. The small indicator size is most apparent when hand flying without a flight director.

For a while I had 2 G5s and a single 275 in my panel, and no AP or FD. While it was not a problem to fly an LPV approach using the small path indicators on the G5s, it was really extra nice to put the 275 into CDI mode on final approach and have the big bright vertical deviation line for reference - so much easier to use imho. I agree that the lateral information is presented very well with an HSI, it’s just that the vertical display could have been done better on these particular instruments.

So while you don’t really “need” an extra 275, it is really nice to have it - not only for the CDI display, but for the other pages available that can’t be displayed on the primary 275 HSI.

 

[midlifeflyer]

The glideslope/path indicators on the G5 and 275s are adequate but really a bit small in my opinion. A flight director helps tremendously when following vertical guidance, so that the size of the primary vertical deviation indicator becomes less important. The small indicator size is most apparent when hand flying without a flight director.

That seems to make sense, but it really hasn’t been an issue with those I know who have switched from analog to GI275 (or G5).

I suspect there is something about the ADI’s layout and use of high resolution and color which allow it compactness to not be a major factor for many.

Funny… Personally, I still have more difficulty flying IFR from the right seat with a G1000 than with a pair of the smaller units.

 

[WDD]

The glideslope/path indicators on the G5 and 275s are adequate but really a bit small in my opinion. A flight director helps tremendously when following vertical guidance, so that the size of the primary vertical deviation indicator becomes less important. The small indicator size is most apparent when hand flying without a flight director.

For a while I had 2 G5s and a single 275 in my panel, and no AP or FD. While it was not a problem to fly an LPV approach using the small path indicators on the G5s, it was really extra nice to put the 275 into CDI mode on final approach and have the big bright vertical deviation line for reference - so much easier to use imho. I agree that the lateral information is presented very well with an HSI, it’s just that the vertical display could have been done better on these particular instruments.

So while you don’t really “need” an extra 275, it is really nice to have it - not only for the CDI display, but for the other pages available that can’t be displayed on the primary 275 HSI.

So, am I reading this correctly that the HSI 275 can be turned into a simple CDI when you're approaching final? Or, just skip that entire premise and fly the final using the deviation markers on the AI 275? Or, do both?

 

[midlifeflyer]

So, am I reading this correctly that the HSI 275 can be turned into a simple CDI when you're approaching final? Or, just skip that entire premise and

I forget if you can in all installations. But you really don't want to. Two reasons.

1. If you have never flown with any HSI before, once you learn how you will be thrilled with the enhanced situational awareness created by superimposing the CDI over the DG.
2. The main visual difference between a traditional HSI and an eHSI is the VDI. Most people get used to that within a very short period of time.

fly the final using the deviation markers on the AI 275? Or, do both?

Not a traditional CDI, but there's a bit of personal preference there. Especially when you have a Flight Director, it's really easy enough to fly the complete picture presented by the ADI with just glances at the eHSI (no scanning has not gone away; it has just changed). OTOH, others like the familiarity and comfort of using an HSI as "primary" for heading and course. Plus, because it is not the ADI, there's room for more information, such as the Current Track indicator which can be great for establishing a wind corrected heading.

 

[flyingcheesehead]

Doing some planning, and thinking of putting in dual G 275 (besides getting rid of vacuum system, they will also be needed to drive new AP).

For those who have G 275s or even G5s, what is your experience with flying approaches compared to the mechanical old school CDI? Specifically, the glide slope?

Before I ever flew with an HSI, I thought I'd want the traditional glideslope needle too.

Then my club got a couple of glass panel planes, and then I bought one with a mechanical HSI. I have never missed the glideslope needle. Like anything else, it's just in a different place now - And an HSI gives you far more information at a glance, so it makes interpretation of the overall presentation of information from your instruments easier, even if maybe a needle is easier to see - And honestly, I don't think a needle is easier any more. It's bigger *within the context of the instrument it's in* but it's also completely outside of the 6-pack, meaning you need a bigger scan to see it in the first place.

TL;DR: The diamonds/arrows used for glideslope/path in HSIs are just as easy to use as a traditional CDI glideslope needle, if not better.

Should I even consider adding a third G 275 as a dedicated CDI to mirror the glide slope information that would be shown on the G275 acting as the HSI?

I mean, you could, but you'd be spending a lot of money that you'll end up not using... At least, until you discover all of the other things that the GI275 MFD can do. Whether that's worth it to you is a question only you can answer.

Subscribe to synthetic vision and put the FPM on the runway. Coupled with a GFC500, just match up the chevrons with the flight director.

That said, I personally think the synthetic vision would be more of a feature than a benefit but I could be wrong on that too.

The Flight Path Marker is a fantastic tool. I'd get synvis for that alone.

I highly recommend you do a good comparison of the 275 vs the G5. Although the 275 is physically smaller, it actually has a bigger image, sharper screen, and I think better features. I’m kinda surprised they still sell the G5s after the 275s rolled out. But again, I could be overlooking something.

Yes. The screen is much sharper and brighter, and the HSI representation is larger on the 275 than it is on a G5. There are reasons they still sell it - The 275 is more expensive, so I'm sure they still sell plenty of G5s to cost-conscious customers. I think there are also scenarios where the G5 may be a better solution in a particular installation with interactions with other things taken into account, but mostly I think it's just the budget offering now.

BTW: I may be mistaken but I think there’s a 275 option that’ll let you scroll between HSI and CDI but I don’t think that model can be used as a backup for the 275 that’s a primary ADI for some reason.

So, am I reading this correctly that the HSI 275 can be turned into a simple CDI when you're approaching final? Or, just skip that entire premise and fly the final using the deviation markers on the AI 275? Or, do both?

The unit that is an HSI and a backup AI cannot be switched over to a simple CDI. The MFD version that isn't providing primary reference for anything can be a simple CDI. Since generally people install the 2nd 275 as a backup to the first one, this usually means you need a third GI275 to be the MFD. Get a fourth one with EIS and you can tear darn near everything else out of your panel.

 

[bkspero]

I've had one frustration with my 275's. They do not show the compass direction for the tail of the course arrow. For example when flying the outbound leg of a hold or a course reversal you need to know the heading to turn to for the inbound leg. I was trained that the easiest way to do that was to simply look at the bottom of the compass rose on my DG. No need for mental arithmetic. Just turn to that heading (or thereabouts for the wind correction).

In most cases this won't be an issue as my GPS will be prompting the turn. But if anything happens to the GPS and I need to hand fly an ILS or VOR approach without its assistance, it would be really nice to be able to just glance down and see the reverse course without the distraction of the mental math. But with the 275 Garmin put a bunch of other information at the bottom of the compass rose and that stuff blocks the view.

As a fall back I had the shop leave the Nav2 CDI installed. I rarely use it as a CDI, but its compass rose provides the reverse course information missing from the 275s. Also, the G5 unit does not suffer from this issue.

 

[midlifeflyer]

I've had one frustration with my 275's. They do not show the compass direction for the tail of the course arrow.

Yeah, it kind of covers that piece. But I get that information from the chart, so it’s not exactly a mystery.