Garmin 430

A

azaviator08

New Member
I am reading in the FAA instrument book and it says that when doing approaches you have to arm the approach within 30nm. Is this the same thing as activating the approach?

Can you use the GPS to legally fly an NDB approach? I know how you load it and all that to make it use the NDB to navigate, but is it legal to shoot an NDB approach using the GPS??
 
No. Nor is it legal to use the GPS to shoot an ILS, LOC, VOR etc. You can use it for DME or situational awareness but you have to get your course information from the instrument.

The only approach you can get course guidance for from the GPS for is a GPS approach.
 
Though you could "cheat" a little if your aircraft has the capability to display both RMI and CDI indications at the same time. Use the CDI for quick course guidance and verify it's accuracy with the RMI/ADF card and you're set. Just don't omit the ADF card.
 
cencal83406 said:
However, many NDB approaches are starting to say "NDB or GPS" in the header...
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If you look back, I think you'll find the history is exactly the opposite. Less and less NDB approaches are saying "NDB opr GPS" in the header.

Early GPS approaches were simple overlays ("...or GPS") on existing NDB and VOR approches. TERPS criteria had already been met for the configuration and it was simply a matter of the FAA confriming that there weren't any glitches when the same approach was flown GPS-only. As RNAV approach design became more sophisticated the movement has been away from that - first to stand-alone GPS approaches that were virtually identical to the old overlay, except for the use of GPS-only wayponts. And then to a competely new RNAV/GPS approach that didn't look much like the old overlay except for the location of the FAC. And of course to the GPS approach "where no man has approached before."

I'd be very surprised if there were "many" of the "NDB or GPS" approaches left. I'd be less surprised if there were none of them left.
 
MidlifeFlyer said:
If you look back, I think you'll find the history is exactly the opposite. Less and less NDB approaches are saying "NDB opr GPS" in the header.

Early GPS approaches were simple overlays ("...or GPS") on existing NDB and VOR approches. TERPS criteria had already been met for the configuration and it was simply a matter of the FAA confriming that there weren't any glitches when the same approach was flown GPS-only. As RNAV approach design became more sophisticated the movement has been away from that - first to stand-alone GPS approaches that were virtually identical to the old overlay, except for the use of GPS-only wayponts. And then to a competely new RNAV/GPS approach that didn't look much like the old overlay except for the location of the FAC. And of course to the GPS approach "where no man has approached before."

I'd be very surprised if there were "many" of the "NDB or GPS" approaches left. I'd be less surprised if there were none of them left.
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There's some still left. Not as many as there once was when GPS IAPs were coming out, as you describe. In AZ, off the top of my head, I know P19, KFFZ, KSDL, KRYN and KOLS still have them. But how long they're going to last, or if they're just left there "just because", is unknown to me.
 
azaviator08 said:
I am reading in the FAA instrument book and it says that when doing approaches you have to arm the approach within 30nm. Is this the same thing as activating the approach?
Click to expand...
I don't think anyone addressed this part of the question. I'll give it a shot.

As you've probably learned, an approach-certfied GPS has three modes, en route, terminal and approach, with increasingly tighter tolerances for the CDI. "Arming" the approach just means setting the GPS up to change those tolerances. In theory, this can be manual, although in practice, most (all?) approach GPS (definitely the 430) automatically make the transtitions, so your job is to confirm that it's in the proper mode - which shows up on the face of the GPS. If it hasn't moved to TERM or APR in the right places, somehting is wrong. Could be somehting as complext as a RAIM fialure or as simple as, "duh, I dropped the destination out of my plan."


But I'm curious
 
MidlifeFlyer said:
If it hasn't moved to TERM or APR in the right places, somehting is wrong. Could be somehting as complext as a RAIM fialure or as simple as, "duh, I dropped the destination out of my plan."


But I'm curious
Click to expand...

AFAIK, the only way the GPS will go into APR mode is when, for instance the 430, you have "activated" the approach. You can do this 1 of 2 ways, "Activate the approach" or "Activate-vectors-to-final". If RAIM is not available, the 430 should display some sort of message stating the fact that RAIM is unavailable and the approach is unusable. I'm not sure of the correct verbage. But as far as "arming" the approach, yes.. it is the same as "activating".

Also, I noticed this is in the ATC forum. If it was moved to Genral Topics, you'd get a lot more responses from people like myself who use 530/430s everyday.
 
JulietBravo said:
AFAIK, the only way the GPS will go into APR mode is when, for instance the 430, you have "activated" the approach. You can do this 1 of 2 ways, "Activate the approach" or "Activate-vectors-to-final". If RAIM is not available, the 430 should display some sort of message stating the fact that RAIM is unavailable and the approach is unusable. I'm not sure of the correct verbage. But as far as "arming" the approach, yes.. it is the same as "activating".
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Also: It'll only move into "APR" mode when you actually hit a section of the approach, so if you are still enroute but you already have the approach loaded, it'll still be on leg, once you start getting closer then itll switch to apr or term mode. I want to say it'll switch after the IAF but I don't have that much 430/530/1000 time.
 
elmetal said:
Also: It'll only move into "APR" mode when you actually hit a section of the approach, so if you are still enroute but you already have the approach loaded, it'll still be on leg, once you start getting closer then itll switch to apr or term mode. I want to say it'll switch after the IAF but I don't have that much 430/530/1000 time.
Click to expand...

There is an FAA requirement for when the APR mode must be activated.

When within 2 NM of the FAWP with the approach mode armed, the approach mode will switch to active, which results in RAIM changing to approach sensitivity and a change in CDI sensitivity. Beginning 2 NM prior to the FAWP, the full scale CDI sensitivity will smoothly change from ±1 NM to ±0.3 NM at the FAWP
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mojo6911 said:
There is an FAA requirement for when the APR mode must be activated.
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During my instructing days, our KLN94s would go into APR mode within 2 nm of the IAF indicating RAIM is active. I'll have to pay more attention next time I use our 530 for an approach and see when it switches over. I'm sure it's in a Garmin book somewhere though...
 
mojo6911 said:
There is an FAA requirement for when the APR mode must be activated. "When within 2 NM of the FAWP with the approach mode armed, the approach mode will switch to active, which results in RAIM changing to approach sensitivity and a change in CDI sensitivity. Beginning 2 NM prior to the FAWP, the full scale CDI sensitivity will smoothly change from ±1 NM to ±0.3 NM at the FAWP "
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And you cannot decend on the approach until it does "go active."
 
The Garmin should automatically sequence from ENR to TERM when you are within 30nm of the destination airport and go from TERM to APR within two nautical miles of the FAWP.
 
Not get off topic but here is something that I'm having trouble understanding and has been disscused on a few other forums without a clear answer:

The 430 provides (per garmin's website) seperate recivers for each function (GPS: TSO C129a, Class A1 (en route, terminal, and approach), VOR: TSO C40c, LOC: TSO C36e, GS: TSO C34e) That being said what is there to stop me from using my 430 as a standalone unit for say an ILS provided I have the LOC tuned in my NAV window and am operating in VLOC mode? I'm just trying to understand what if any legalities exist when using a nav function other than GPS that is contained within a stand alone unit like the 430/530.

On a side bar my interp of the AIM in terms of restrictions on GPS approaches is only that your ALT have something other than a GPS only approach which wouldn make since if your first approach was missed b/c of a RAIM type outage ect.......Is there something else that I'm missing?

(AIM 1-1-21.c.6.(h))
"A non-GPS approach procedure must exist at the alternate airport when one is
required. If the non-GPS approaches on which the pilot must rely require DME
or ADF, the aircraft must be equipped with DME or ADF avionics as
appropriate."​
 
That being said what is there to stop me from using my 430 as a standalone unit for say an ILS provided I have the LOC tuned in my NAV window and am operating in VLOC mode? I'm just trying to understand what if any legalities exist when using a nav function other than GPS that is contained within a stand alone unit like the 430/530.
Click to expand...

Short answer: None.

The GNS 430/530 is legal to use for GPS, VOR, VOR/DME, ILS approaches when properly installed as per FAA TSO and meets any STC requirements for your aircraft. You must switch your nav source from GPS to VLOC in order to legally shoot non GPS approaches.

You are correct that your alternate must have an approach other than GPS. Recall 91.205(d)(2) Two-way radio communication and navigation equipment suitable for the route to be flown. As indicated by the AIM you quoted, if your approach requires DME, the failed GPS can no longer provide you with reliable distance information. Failure of GPS doesn't necessarily mean failure of the GNS 430/530. In the event of GPS failure, it would be nice to have an alternative way to get down in IMC.
 
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