Hey all - checking in again. I’m about to pull the trigger on this panel. After lots of thought and consideration, I think I am going to be moving down the G3X+GNX375+G5+GTR205+GFC500 route. I know this point is controversial, but I think I am going to just leave in the KX155 and VOR indicator. If it dies, it dies, and I’ll probably just take it out (it actually appears to be in really good condition, fwiw), but I DO want a second Comm and I DON’T want to spend money on a new Nav/Comm just for looks.
I would merely reiterate my comment about this from post 15: If you're going to keep it, get it refurbished now, replacing all electrolytic capacitors. Otherwise, they'll start leaking acid before too much longer, and you won't know it until the board has been etched and is unserviceable, making the whole radio junk. If you refurb it now, everything but the screen will go another 20 years no problem. The screen, well... That's a gamble. It's $4,000 to replace the screen or $5,000 for a whole new radio at that point.
1) There’s this whole line of discussion that the GNX375 won’t support VNAV. I understand that it won’t fly the step downs on a STAR, for instance, but I want to absolutely confirm that it will intercept and track an LPV or ILS glideslope. One benefit of leaving the VOR in is that I will be legal to fly an ILS. I do not plan to have the autopilot connected to the VOR, so I want to make sure that it will track the “fake” glideslope coming from the GNX375 while the VOR/LOC GS is set up as primary. Obviously, the same question is in play for an RNAV/LPV glideslope, but I am somewhat more confident that this is supported.
VNAV is the ability to automatically start an enroute descent and navigate along a calculated vertical path to a specific point in space. There are several reasons why this might happen. The most common scenario in GA is that you're VFR and you want to hit pattern altitude 3 miles from your destination, for example. IFR, you might want to hit the intermediate altitude at the intermediate fix and use the intermediate leg to slow to approach speed and get configured. If you fly in busy airspace, you may get a STAR or crossing restriction (example: Going into KFCM Flying Cloud "Cross 20 miles east of Farmington at and maintain 4,000.").
VNAV calculates a vertical path from the point in space (fix and altitude) that you set along your flight plan at the angle that you set (you can set a vertical speed, but it'll generally be a bit higher than you set unless you pull power back to maintain the same airspeed during the descent).
To use it, In cruise, you would program in the fix and the altitude you wanted to hit into the GTN flight plan, set your altitude bug to the altitude you want to hit, and push the "VNAV" button on the GFC500 to arm VNAV mode. If you do this way early, you may get asked for confirmation about a minute prior to the top of descent. In any case, when you reach the calculated top of descent, the autopilot will switch into VNAV mode and follow the calculated vertical path down, arriving perfectly at the altitude and fix that you put into the flight plan, and then it will switch back to ALT mode.
VNAV is separate and distinct from the vertical glidepath for an approach. You do NOT need a GTN for that. However, if you're on an ILS you should be on "green needles" - You switch to VLOC mode and your CDI and VDI turn green instead of magenta. It sounds like maybe you're not planning on having a nav radio hooked up to the G3X?? Will you have a separate analog CDI or something?
2) I’ve been thinking that I’d kind of like to be able to leave engine information up at all times or that I might want additional screen real estate in general. In the grand scheme of things, the G3X’s are not that expensive - it’s all the sensors, engine monitoring computer, engine probes, transducers, fuel senders, etc that make them really expensive to buy and install. But if I’m committing to all of that for a single 10” G3X, could I add a second 10” or 7” for basically just the cost of the G3X and minimal additional install labor? If I had a second G3X would that eliminate the requirement for a G5/GI275 backup?
I think you still need the backup. It's worth thinking about the second G3X though. I'm planning on a 10" on the pilot side and a portrait 7" on the copilot side. However, I still plan to have the EIS strip on the 10". It doesn't take up enough space to remove any other functionality, and the EIS *has to* always be visible somewhere, so the reason for keeping the strip on the 10" would be that, while I can put the EIS display fullscreen on the 7" copilot side display while I'm flying by myself, if I'm flying with another pilot they can use that display as their own PFD. If there was no EIS on the 10", I think the 7" has to be locked on EIS.
1. What audio panel do you have? You didn't list one in the new equipment you're putting in. Audio wiring is a major chore, which means lots of labor hours. Paying a lot of money to rewire an old audio panel that might not work or sound as good as a modern unit (e.g. isolation modes, stereo audio, and spatial audio to put Comm1 in the left ear and Comm2 to in the right ear when they're both receiving) isn't a great investment.
This. We did a new audio panel on our first big upgrade for exactly this reason.
For context, I don’t want to hook this autopilot up to the VOR/GS (tracking it from the GPS signal is way better anyway), but I do intend to keep the VOR to be “primary” in this case. While I never really want to fly a VOR or ILS approach again given how much better RNAV is, there’s just a lot of them at primary airports.
You don't hook an autopilot directly to "a VOR" you hook it up to the CDI, which in this case would be the G3X. Are you not going to hook the KX155 to the G3X? If so, what are you going to display your VOR/ILS needles on?
