Why 2 GNS-430's?

I think everone wants two 430's becasue a lot of us grew up thinking the ultimate was two VOR's or better yet dual glideslopes. That was because back in the 60's radio's used to quit. I flew an Aztec fo a living back then and it cost about $200 a month to keep a DME working 1/2 the time! When I bought my Twin Comanche 13 years ago I took out a VOR head to install a storm scope. I had to have 2 VOR's so I installed a KX-125 as a back up com and #2 VOR. I have used the VOR about twice to find an intersection for a hold. That was so long ago I am not sure I remember how to use the VOR in that radio. I now have a 480 with a 106 head and the backup is the 125. The real navigational backup is my 295 soon to be replaced if the 396 ever shows up. In 1800 hours and most of 13 years I've had one transponder failure ( I have a backup now), one com failure of an old MK-12D ten years ago and one display failure in that unit.
 
Steve said:
I suspect its more for redundancy than enhanced capability. Prices on GPS/comm units are approaching what nav/comms were not too many years ago.

my 2% of a dollar
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I think Steve's got it.

Price is comparable to two navcoms, and having the second GPS is useful.

These days, I'd opt for one 430/530 and one 480, plus a separate DME.
 
I think the value of two 430's (or a 430 and a 530) is the ability to display different information on the two units. To some extent, this can be accomplished with a handheld.
 
I agree with all of the above. My plane has a 430/530. Each is coupled to a seperate glide slope. Each has a seperate com/vor feature. If one went out, there is a second. Also, I set the GPSs on different distances when flying to have more perspective and better awareness. I cross tune the VORs to check position.
On instrument approaches, I sometimes have all four frequencies queued up: talk and standby on each for approach, ATIS, Tower and Ground. VOR tuned in for missed.

You certainly can get by with one and some back up system, but two provides redundancy and much better situational awareness and ability to have things tuned in advance. (I hate to admit this, but even with the 430/530, I still carry a hand held radio and back up GPS.)

If I was doing short local flights, wouldn't be as concerned. But as one flies longer cross country flights in poorer weather and over what could be hostile terrain below, more of this makes sense.


Dave
 
If the 430/530 would let you monitor the standby frequencies I wouldn't *have* to have two of them... but I hate "going off freq" to check ATIS or whatever.
 
jdwatson said:
If the 430/530 would let you monitor the standby frequencies I wouldn't *have* to have two of them... but I hate "going off freq" to check ATIS or whatever.
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I think the GNS 480 does have that capability. Maybe Apollo was thinking along the same lines as you.

Then again, as reliable as today's avionics are, they do fail now and then and anyone who regularly flies in IMC would be a bit reckless to fly without a second com and nav source in the panel. Handhelds are OK for backup purposes, but unless you normally have the handheld hooked up and programmed you could become real busy if your one and only GPS/MapCom died while on an approach in IMC at a busy airport. Some pilots do fly with their handheld GPS on and ready, but I don't know of anyone who has their handheld comm connected to the antenna and headset while flying with the panel units.

Another issue is dispatchability. With Dave's setup he could complete a multi leg IFR trip if one of the Garmins died enroute. Whether he would might depend on the weather involved.
 
larrysb said:
I've noticed a lot of newer planes come equipped with dual GPS installation, like 2 GNS430's or a 530 and a 430.

Is there some particular thing you need 2 of them for that you can't do on one? Maybe some kind of VOR/DME approach or something like that?
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Using the Garmin in lieu of DME, you end up without the moving map. If you want moving map + DME, you need two of 'em. Ryan Ferguson had a good writeup about this a while back.
 
flyingcheesehead said:
Using the Garmin in lieu of DME, you end up without the moving map. If you want moving map + DME, you need two of 'em. Ryan Ferguson had a good writeup about this a while back.
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Exact reason I was given. I think the multiple screens are helpful. An MX20 could help solve this as well.
 
larrysb said:
How about a 430 doing the DME job and a hand held on the yoke for the moving map? The moving map being "an aid to situational awareness" anyway.

Is there a case where two IFR approved GPS are required? Or is there another operating condition where only a pair of 430/530 would be satisfactory?

I've also heard that with the apropriate jack installed, the 430 can output serial data to a Garmin handheld, which would seem to help things a lot. My 296 has a much nicer map and terrain feature than a 430. Of course, the 296 is not legal for navigation.
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I know of no situation where two IFR GPS's would be required for part 91 over the continental US. I vaguely recall something requiring redundancy for part 121 when crossing oceans. That said, there are times when a DME distance, course guidance, and a map display are useful, and the first two must come from approved sources. Since maps aren't a requirement their's no signifcant advantage to getting that from a handheld especially if the HH is able to display a route from the panel GPS. Otherwise you've got extra work to program both.
 
and don't forget that having two 430s/530s allows Jeppesen to charge you even more every month (but those generous guys do give a little discount if you have two in the same plane). :rolleyes:
 
Lance F said:
and don't forget that having two 430s/530s allows Jeppesen to charge you even more every month (but those generous guys do give a little discount if you have two in the same plane). :rolleyes:
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I think a lot of folks with 2 Garmins keep one current and one a month behind, only paying for one subscription.
 
How big will our iap chart files get when they add all those waas approaches? We will be forced to go paperless? Or will they drop a bunch of other approaches? Maybe it will be a chance to sell us the books by county instead of the steadily smaller regions?!
 
lancefisher said:
I think a lot of folks with 2 Garmins keep one current and one a month behind, only paying for one subscription.
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The only problem with this is that the crossfill function will not work if the databases are not identical. They both need to have the same dates for the Garmins to crossfill.
 
lancefisher said:
I think the GNS 480 does have that capability. Maybe Apollo was thinking along the same lines as you.

Then again, as reliable as today's avionics are, they do fail now and then and anyone who regularly flies in IMC would be a bit reckless to fly without a second com and nav source in the panel. Handhelds are OK for backup purposes, but unless you normally have the handheld hooked up and programmed you could become real busy if your one and only GPS/MapCom died while on an approach in IMC at a busy airport. Some pilots do fly with their handheld GPS on and ready, but I don't know of anyone who has their handheld comm connected to the antenna and headset while flying with the panel units.

Another issue is dispatchability. With Dave's setup he could complete a multi leg IFR trip if one of the Garmins died enroute. Whether he would might depend on the weather involved.
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When I fly single pilot IFR I have my handheld KX 99 connected into it's own external antenna and it also has it's own press to talk button ready to velcro onto the yoke. So all I would have to do in plug into my headset and turn the unit on and I am back up running with a great com system. Dual I leave it in the seat pocket ready to connect to the external antenna. I have a 250 xl in the panel and also a pilot III that is dash mounted and hard wired into the electrical system so the internal batterys stay fully charged. I also program both GPS prior to engine start and takeoff. So in the event of a full electrical outage I am still not ever without GPS or Comm. I went through that once and it caused me to have to buy new shorts so now I am prepared to never let that happen again. So now you know of at least one of us who does have there handheld ready to go.
 
I have my GPS III Pilot connected to my 430. Any flight plan in the 430 is transfered to the GPS III Pilot. I usually have the GPS III Pilot displaying the HSI page and the 430 showing the map page. This makes for easy enroute and approach navigating. Much less cost than two 430's or 530's. You don't have to update the database in the GPS III Pilot as all the waypoints come from the 430 database
 
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