jnmeade
Cleared for Takeoff
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?
Is an electrical failure the only way that you could lose a 430?Unless the 430s are on separate electrical supplies, seems a waste to me.
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.Why not a 430 and a handheld, battery-powered GPS for backup?
For the same reason you two radios. It's all about redundancy
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.
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.
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.