Upgrade or Downgrade

[RoundTwo]

I’m interested in hearing your opinion on the value of a panel change in a J I’m looking at. I know there are threads on the pluses and minuses of the 355, but I’m looking for subjective thoughts on this panel as it is. 

First photo needs no introduction. Second photo shows a GNC355 that goes to a G5 and a GNC255 going to a GI275 CDI. The KMA24 was swapped out for the PMA7000B as well.

Do you feel this was a step forward or backward because of the lack of NAV in COM 1. I am intending on getting my instrument ticket in the plane I end up purchasing and wonder if the lack of a second NAV will complicate that goal and cause any headaches down the road for cross country travel.

R2

 

 

[Rwsavory]

For the last 10 years I’ve had both a WAAS GPS and nav/com, and I have yet to encounter a situation where an rnav approach wasn’t available. Not to say that that it couldn’t happen, and it’s nice to have the vor/ILS, but I think that’s the reality of where we are now. As far as training, I think it would be worthwhile learning to do the ILS. It’s quite different from doing RNAV approaches. You could rent another airplane for that part of your training. It would be easier doing your check ride in something like a C172 anyway.

[dzeleski]

Well its definitely not a downgrade. I think since you have both types of nav covered you are mostly good. That being said I personally would like to see some type of functionality duplicated on the second unit even if its just a localizer/vor.

Have you also considered what AP this is going to integrate with if any? You'll want to make sure this is compatible with that if you plan on going that route.

The 650XI is another 4-5k, you may want to consider that paired with the GNC255 if your budget allows. Quote both, see what the difference is.

[EricJ]

Looks like an awesome panel to me!   That's all upgrade.

 

[RoundTwo]

13 minutes ago, dzeleski said:

Well its definitely not a downgrade. I think since you have both types of nav covered you are mostly good. That being said I personally would like to see some type of functionality duplicated on the second unit even if its just a localizer/vor.

Have you also considered what AP this is going to integrate with if any? You'll want to make sure this is compatible with that if you plan on going that route.

The 650XI is another 4-5k, you may want to consider that paired with the GNC255 if your budget allows. Quote both, see what the difference is.

Thanks for the great input. Lack of redundancy is what keeps tripping me up, but we’re moving further and further into a GPS world so maybe I’m over reacting. Currently, it has an S-Tec 30, so not much of an AP. If someone else was writing checks, there’s plenty of space for a GFC500.

[RoundTwo]

56 minutes ago, Rwsavory said:

For the last 10 years I’ve had both a WAAS GPS and nav/com, and I have yet to encounter a situation where an rnav approach wasn’t available. Not to say that that it couldn’t happen, and it’s nice to have the vor/ILS, but I think that’s the reality of where we are now. As far as training, I think it would be worthwhile learning to do the ILS. It’s quite different from doing RNAV approaches. You could rent another airplane for that part of your training. It would be easier doing your check ride in something like a C172 anyway.

I agree about check ride in the 172 being a wise move. Thanks!

[Ragsf15e]

2 hours ago, RoundTwo said:

I’m interested in hearing your opinion on the value of a panel change in a J I’m looking at. I know there are threads on the pluses and minuses of the 355, but I’m looking for subjective thoughts on this panel as it is. 

First photo needs no introduction. Second photo shows a GNC355 that goes to a G5 and a GNC255 going to a GI275 CDI. The KMA24 was swapped out for the PMA7000B as well.

Do you feel this was a step forward or backward because of the lack of NAV in COM 1. I am intending on getting my instrument ticket in the plane I end up purchasing and wonder if the lack of a second NAV will complicate that goal and cause any headaches down the road for cross country travel.

R2

 

 

I don’t think you need two navs.  BUT… having the only ils piped into an “obs” type display is a significant downgrade from having it displayed on your hsi.  It’s good enough for a backup but means you’ll probably never use it by choice.  Me?  I’d have them both available on my hsi, one nav and one ils.  You will have to think about failure of that display, but that’s rare and has backups on the primary probably.  If you’re only able to put the iks on the obs always, that’s gonna be like that every flight.

My current nav 2 only displays on the obs but I have nav 1 on the hsi so it’s more of a backup and i can use the ils normally.

fyi, ksff, runway 21, no gps aporoach, only ils,  Runway 4, no ils, only gps!

[RoundTwo]

10 minutes ago, Ragsf15e said:

I don’t think you need two navs.  BUT… having the only ils piped into an “obs” type display is a significant downgrade from having it displayed on your hsi.  It’s good enough for a backup but means you’ll probably never use it by choice.  Me?  I’d have them both available on my hsi, one nav and one ils.  You will have to think about failure of that display, but that’s rare and has backups on the primary probably.  If you’re only able to put the iks on the obs always, that’s gonna be like that every flight.

My current nav 2 only displays on the obs but I have nav 1 on the hsi so it’s more of a backup and i can use the ils normally.

fyi, ksff, runway 21, no gps aporoach, only ils,  Runway 4, no ils, only gps!

Great point! Thanks.

R2

[Fly Boomer]

4 hours ago, RoundTwo said:

Do you feel this was a step forward or backward because of the lack of NAV in COM 1

Used to be, one GPS and two NAVs was the thing.  Now, if you can't have it all, it seems that it's common to have one NAV and two GPSs.  Either way, you probably need two COMs.  The way ILS approaches are disappearing, and the proliferation of GPS approaches, this evolution makes sense.  I took a run at an airplane with two GNS-430s and a G500.  While the 430s are a bit hard to see, it would never be a problem because everything you would want to look at would be displayed on the G500.  In my mind, the bonus was two of everything:  NAV, COM, and GPS.

[hammdo]

2 coms helps tremendously. I just did my IFR ticket. 
 

I have 2 G5s, PMA7000Mb, gnc 355, gtx 327 and kx155 nav/comm/gs. If I change anything it’s the gtx 327 - for a gnx 375 ;o)

-Don

[OR75]

for IFR 

2 COMMs and 1GPS and 1 VOR

definitely an upgrade from a visible standpoint but lost Navigation capability in case of GPS loss (GPS signal or GPS unit loss) 

 

 

[larryb]

I think the 355 + 255 is fine for IFR. You have 1 gps, 1 nav, and 2 comms. In my 10 years of IFR I have not needed more than this.  You do not need a second nav for an ILS because the GPS unit can substitute for the missing second VOR to identify any intersections. Does the 255 also feed the G5? If not, that will be slightly awkward, you'll be looking at the G5 for GPS approaches and the GI275 for ILS approaches.

 

I looked up the list prices, for $10K more the plane could have had twin GTN650xi's.  The only benefit to dual 650's is redundancy in case of a failure.

 

Is this panel already installed in a plane you are already considering? Or is this what you plan to install after buying the plane?

 

Larry

 

 

[RoundTwo]

7 minutes ago, larryb said:

Does the 255 also feed the G5? If not, that will be slightly awkward, you'll be looking at the G5 for GPS approaches and the GI275 for ILS approaches. - Great question. I’ll have to find out for sure.

Is this panel already installed in a plane you are already considering? Or is this what you plan to install after buying the plane?  - This is an existing panel in a prospect plane.

See inline comments. 

[Ragsf15e]

1 hour ago, RoundTwo said:

See inline comments. 

Generally the radios only feed one display.  Unless the displays themselves are linked like 2xg5s.

[RoundTwo]

28 minutes ago, Ragsf15e said:

Generally the radios only feed one display.  Unless the displays themselves are linked like 2xg5s.

That is my guess as well.

[Utah20Gflyer]

I went with the 355 and one other nav/com like you are describing.  I use the GPS for cross country navigation almost exclusively now.  Its just so easy and convenient.  Punch in the flight plan before takeoff and you are good to go.   Its almost like the nav is just a back up device and for training.  I pad with gps provides additional redundancy and in a lot of ways is superior to a nav radio except in terms of legal IFR navigation. 

[Ragsf15e]

2 hours ago, Utah20Gflyer said:

I went with the 355 and one other nav/com like you are describing.  I use the GPS for cross country navigation almost exclusively now.  Its just so easy and convenient.  Punch in the flight plan before takeoff and you are good to go.   Its almost like the nav is just a back up device and for training.  I pad with gps provides additional redundancy and in a lot of ways is superior to a nav radio except in terms of legal IFR navigation. 

Yeah, no reason at all to use vhf nav as long as gps is working.  Keeping current and using the ILS if you want to be ifr proficient is probably worthwhile though.

[hubcap]

18 hours ago, Ragsf15e said:

Yeah, no reason at all to use vhf nav as long as gps is working.  Keeping current and using the ILS if you want to be ifr proficient is probably worthwhile though.

I agree completely with this comment. I intentionally request the ILS from time to time for this purpose.

[DCarlton]

I read the thread quickly but for me, I'd always want dual COMMS, GPS, and VOR/ILS capability.  I use ILS frequently and occasionally use the VOR NAV.  

[rbp]

On 12/9/2022 at 12:15 PM, Fly Boomer said:

Used to be, one GPS and two NAVs was the thing.  Now, if you can't have it all, it seems that it's common to have one NAV and two GPSs.  Either way, you probably need two COMs.

I went this way, with a GTN750xi NAV/COM/GPS and a GFC355 COM/GPS, based on the insanely low probability of my ILS receiver being OTS simultaneous with a GPS outage 

[RoundTwo]

1 hour ago, rbp said:

I went this way, with a GTN750xi NAV/COM/GPS and a GFC355 COM/GPS, based on the insanely low probability of my ILS receiver being OTS simultaneous with a GPS outage 

That sounds like a great setup. Do you have any panel pictures?

[Ragsf15e]

11 hours ago, rbp said:

I went this way, with a GTN750xi NAV/COM/GPS and a GFC355 COM/GPS, based on the insanely low probability of my ILS receiver being OTS simultaneous with a GPS outage 

A few people have complained that the 355 and gtn series don’t work well together.  Have you noticed this? Has it been an issue?  Seems like an awesome setup.

[rbp]

19 hours ago, RoundTwo said:

That sounds like a great setup. Do you have any panel pictures?

 

Yes, the GTN750 doesn't crossfill to the 355. So its more like a standby rather than an integrated system. Supposedly there is an update for the 355 in the works to remedy.

[jlunseth]

Just some random thoughts, and I am thinking more about training for and doing the IFR checkride than travel once you have it, because you have more flexibility once the ticket is yours, that is, you typically get to choose the approach you want unless in heavily trafficked airspace. First, it is true that there are lots of RNAVs around but any time you are around Bravos, Charlies and Deltas the standard is still VTF ILS. The controllers have much more confidence in ILS VTF than RNAV, and the RNAV’s are always longer routes, they would rather get you on the approach and down out of the sky so they can deal with the next traffic. For ILS purposes it is much better to have the NAV radio connected to an HSI than an OBI so you don’t have to deal with reverse sensing. Dial in the inbound leg and just follow the needle. For the checkride, don’t you need to be prepared to do three different approach types? It’s been awhile since I did my ticket, but it seems to me that was what the PTS required at the time. The examiner would pick two. But doesn’t that mean you must be ready to do a VOR? And if so, there is a relatively new quirk. I have a GTN750 as primary and it really does not want to give me VLOC control for a VOR, I really have to push a lot of buttons to get it to do that. Apparently there is an AC out that it is permissible to use RNAV GPS to fly a VOR approach provided you monitor on an actual nav/VLOC set up. So I let the GTN do its RNAV thing on a VOR and I usually get VNAV guidance to boot, but I put the VOR on my second GPS, a 430AW, and put that in VLOC mode. It displays on its own OBI, so I am monitoring. I think your set-up would do that.

I have dual everything for actual travel. I have had radios burn out and go dark. Can’t have enough of them. That goes for Nav radios also. GPS outages are also real, they are not common but they are real. There seem to be spots, small areas that are worse than others, doesn’t help if you happen to be doing an approach in one of those spots.

[rbp]

6 hours ago, jlunseth said:

. I have a GTN750 as primary and it really does not want to give me VLOC control for a VOR, I really have to push a lot of buttons to get it to do that.

on the 750, once you load and activate a VOR approach procedure, it will load the VOR's frequency into the VLOC radio, automatically identify and translate the morse code, then you can hit the CDI button to change the CDI from magenta (GPS) to green (VLOC). what other buttons are you pushing?