Why dual 430's?

[jnmeade]

I'm asking as a person who has flown the Garmin 430 a few times but am not expert in it. What is the advantage and value of having dual 430's?

 

[jtheune]

For the same reason you two radios. It's all about redundancy

 

[dmccormack]

Unless the 430s are on separate electrical supplies, seems a waste to me.

Why not a 430 and a handheld, battery-powered GPS for backup?

 

[mantakos]

Unless the 430s are on separate electrical supplies, seems a waste to me.

Is an electrical failure the only way that you could lose a 430?

Why not a 430 and a handheld, battery-powered GPS for backup?

If my budget required me to choose, I'd certainly rather have a 430, a 396, and a nav/comm as opposed to two 430s and no handheld. But my guess is that, for many, the answer is two 430s _and_ a handheld GPS.

But unlike a handheld GPS, a 430 includes a comm radio, a VOR/LOC/GS, and it isn't an "emergency measure" to perform GPS approaches with it.
-harry

 

[Areeda]

We have dual 430W's in our Cirrus along with the Avidyne MFD. Besides making it very embarrassing to get lost or overfly our destination there are a few advantages.

One is the ability to display different pages on the 3 units.

Another is when doing multiple approaches in succession you can set up the next one one in GPS 2 and transfer it when ready.

Now does all this mean I'd upgrade a panel with 2 units? I'm not sure, certainly not on the current budget.

We do have redundant electrical systems (battery, alternator and isolated busses).

Joe

 

[flyersfan31]

Along with 2 nav/coms, 2 430s provide more info - moving map on one, dedicated traffic page on the other, for example, or the flightplan page.

 

[GMascelli]

I'll take the 530 with the panel mounted 496 for wx and traffic and if the electrical goes TU I'll have plenty of battery on the 496.

 

[Ted]

For the same reason you two radios. It's all about redundancy

Yep. Issues could pop up with one GPS (as we know, nothing is 100% reliable) that wouldn't impact the other one. Failure of the unit, bad connections, etc.

Personally, I wouldn't spend the money. I have a KLN 94, KX155A, and MX170. My backup GPS is a hand-held unit that is battery powered. What I also like about it is I can use it to shoot approaches. Yes, it's illegal, but if my electrical system has failed and there's no VMC that I'm aware of anywhere, I'll put 91.3 to use.

Always good to practice such things first so that if it happens for real, you know how it works!

 

[gismo]

My airplane has a single GNS480 (a more IFR oriented GPS that's somewhat similar to the 430W) along with a KX155 and I have considered replacing the 155 with a second 480. My main incentives are:

1. If one quits, I still have a legal IFR GPS I can use for all available approaches except NDB.
2. Two 480s will communicate with each other and share flight plans and radio frequencies (two 430s will do the same).
3. What Joe said about setting up the next approach (although the 480 makes this easier than the 430 when you only have one).
4. Asthetically dual identical units look better.

That said I haven't gone that route (yet), mostly because 480s are pretty difficult to come by and even used ones sell for more than I paid for mine when new. And I'd probably have to remove my KN64 DME to make room and I've always considered that a good backup should the whole satellite based navigation system fail at some point (even though I almost never use it anymore).

 

[wabower]

If you lose external power and need to fly for a while, consider disconnecting the XM. Battery life is reduced by about 50% when using the XM.

I'll take the 530 with the panel mounted 496 for wx and traffic and if the electrical goes TU I'll have plenty of battery on the 496.

 

[nddons]

I learned to fly in a Symphony with a 430 and 420. It was a pretty sweet set-up for a trainer (this is identical to the one that I flew):

 

[Ted]

That said I haven't gone that route (yet), mostly because 480s are pretty difficult to come by and even used ones sell for more than I paid for mine when new. And I'd probably have to remove my KN64 DME to make room and I've always considered that a good backup should the whole satellite based navigation system fail at some point (even though I almost never use it anymore).

Interesting that you never use your DME. When I was flying the Mooney (which had an IFR GPS plus a DME) I still used the DME, primarily for a backup. I make a habit of dialing in VORs when I'm en-route (especially when flying direct) and it was nice to know distance as well as radial off of it. I also prefer using it for approaches that include a DME, mainly because I would have the GPS set to something else (normally the airport). I've actually thought about putting one in the Aztec, but it's one of those things where it's a nice backup. Like I said, it was a nice-to-have, not something I actively used frequently.

 

[jmaynard]

When the antenna cable falls off the antenna and you see NO GPS DATA on the screen, it's more than just nice to have another one that you can use.

 

[gismo]

Interesting that you never use your DME. When I was flying the Mooney (which had an IFR GPS plus a DME) I still used the DME, primarily for a backup. I make a habit of dialing in VORs when I'm en-route (especially when flying direct) and it was nice to know distance as well as radial off of it. I also prefer using it for approaches that include a DME, mainly because I would have the GPS set to something else (normally the airport). I've actually thought about putting one in the Aztec, but it's one of those things where it's a nice backup. Like I said, it was a nice-to-have, not something I actively used frequently.

The 480 provides GPS based "DME" distance (displayed on all pages) to whatever VOR you have tuned in so the real DME is pretty redundant as long as the GPS is still working.

 

[flyersfan31]

Would I spend money installing 2 430s? No probably not. I'd think more about an MFD and a 430, assuming an existing nav/com like a kx155.

 

[Ted]

The 480 provides GPS based "DME" distance (displayed on all pages) to whatever VOR you have tuned in so the real DME is pretty redundant as long as the GPS is still working.

Ahh! Makes sense. I wish my GPS had that feature.