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View Full Version : "Stand Alone" Boxes (Garmin 430) - Sole means of navigation - legal?


Richard
September 24th 03, 02:54 PM
Probably this has been answered in this forum previously, but I can't find
it. Sorry.

I recently got into a friendly discussion with a knowledgable CFII who said
a Garmin 430 could not be legally used as "sole means of navigation".
Looking back, I think what he means is that "GPS" (even IFR certified units)
can not be used as sole means. Since the Garmin 430 contains not only TSO'd
GPS but also VOR, LOC, GS, etc., my position is that this unit (without any
other navigation equipment on board) is legal as a "stand alone" for use en
route, terminal, and approach . (I know charts are still necessary.)
Please advise.

The following came off the Garmin web site:
******************
GPS: TSO C129a, Class A1 (en route, terminal, and approach)

VOR: TSO C40c

LOC: TSO C36e

GS: TSO C34e

VHF COM: TSO C37d, Class 4 and 6 (transmit) and TSO C38d, Class C and E
(receiver)

The GNS 430 is the most versatile panel-mounted product GARMIN has produced
to date. It combines GPS navigation, VHF communication, and moving map
graphics on a big color display. This "all in one box" 12-channel unit
offers IFR GPS, ILS, VOR, LOC and glideslope capability in a single,
space-saving package

**************************

Dave Pascoe KM3T
September 24th 03, 03:27 PM
I don't believe that is right. I think when they refer to "sole means
of navigation" they mean that you need to have other means of
navigation (separate NAV receiver). Think about it from a safety
point of view, forgat the legal requirements for a moment. If you
were in the soup and your Garmin died, what would you do? I would
never trust one instrument. The all-in-one feature of advanced GPS
units is nice, but you could lose the whole thing.

-Dave
PP-ASEL-IA

paul k. sanchez
September 24th 03, 03:44 PM
>Probably this has been answered in this forum previously, but I can't find
>it. Sorry.
>
>I recently got into a friendly discussion with a knowledgable CFII who said a
Garmin 430 could not be legally used as "sole means of navigation".
>Looking back, I think what he means is that "GPS" (even IFR certified units)
can not be used as sole means. Since the Garmin 430 contains not only TSO'd
GPS but also VOR, LOC, GS, etc., my position is that this unit (without any
other navigation equipment on board) is legal as a "stand alone" for use en
route, terminal, and approach . (I know charts are still necessary.)
>Please advise.
>

I would suggest finding another CFII who knows the TSO's. Absurd for someone
who is supposed to know material to make a statement like that. This is the
kind of CFII who insists that DME is required when flying above FL240, and the
a VOR receiver check is required <30 days prior to doing an ILS or localizer
approach while on an IFR clearance. Ridiculous.


paul k. sanchez, cfii-mei
on eagles’ wings
2011 south perimeter road, suite g
fort lauderdale, florida 33309-7135
305-389-1742 wireless
954-776-0527 fax
954-965-8329 home/fax

ArtP
September 24th 03, 03:51 PM
On Wed, 24 Sep 2003 13:54:37 GMT, "Richard" > wrote:

>
>The GNS 430 is the most versatile panel-mounted product GARMIN has produced
>to date. It combines GPS navigation, VHF communication, and moving map
>graphics on a big color display. This "all in one box" 12-channel unit
>offers IFR GPS, ILS, VOR, LOC and glideslope capability in a single,
>space-saving package
>

The GNS430 box with an external CDI is legal as the sole means of
navigation. Even if the GPS fails you still have a VOR which is legal
as the sole means of navigation. As for backup a single GNS430 is no
worse than a single VOR which is also legal for IFR navigation.

Robert Moore
September 24th 03, 04:17 PM
Dave Pascoe KM3T wrote

Generally speaking, your entire post is incorrect.

> I don't believe that is right. I think when they refer to "sole
> means of navigation" they mean that you need to have other means
> of navigation (separate NAV receiver).

A "means" of navigation refers to a "system" of navigation, not
the devices used to accomplish that means. ADF,VOR,GPS are means,
a King VOR receiver is a device to accomplish a means of navigation.


>If you were in the soup and your Garmin died, what
> would you do? I would never trust one instrument.

Many parts of the world still rely on the NDB/ADF system for
navigation. What would one do if that one ADF receiver fails?
Airliners navigated across the ocean for years using only one
LORAN A receiver.


Bob Moore
ATP CFII

Ron Natalie
September 24th 03, 04:30 PM
"Richard" > wrote in message t...

> Looking back, I think what he means is that "GPS" (even IFR certified units)
> can not be used as sole means.

That is more-or-less true. If you're going to use the GPS to fly an approach
you're required to be able to get into an alternate without it.

> Since the Garmin 430 contains not only TSO'd
> GPS but also VOR, LOC, GS, etc., my position is that this unit (without any
> other navigation equipment on board) is legal as a "stand alone" for use en
> route, terminal, and approach

Yep. As a matter of fact, many new aircraft are delivered with only 430/530's
as nav equipement.

>. (I know charts are still necessary.)

Charts are never strictly required for us small fry. As a practical matter, you
need them, but only perverse misinterpretations of the regulations require their
carriage.

Steven P. McNicoll
September 24th 03, 04:54 PM
"Dave Pascoe KM3T" > wrote in message
...
>
> I don't believe that is right. I think when they refer to "sole means
> of navigation" they mean that you need to have other means of
> navigation (separate NAV receiver).
>

Hmmm.... That would mean that IFR flight with a single NAV receiver is
illegal.


>
> Think about it from a safety
> point of view, forgat the legal requirements for a moment. If you
> were in the soup and your Garmin died, what would you do? I would
> never trust one instrument. The all-in-one feature of advanced GPS
> units is nice, but you could lose the whole thing.
>

Do you trust one electrical system to power all of your NAV gear?

Tarver Engineering
September 24th 03, 05:56 PM
"Richard" > wrote in message
t...
> Probably this has been answered in this forum previously, but I can't find
> it. Sorry.
>
> I recently got into a friendly discussion with a knowledgable CFII who
said
> a Garmin 430 could not be legally used as "sole means of navigation".
> Looking back, I think what he means is that "GPS" (even IFR certified
units)
> can not be used as sole means. Since the Garmin 430 contains not only
TSO'd
> GPS but also VOR, LOC, GS, etc., my position is that this unit (without
any
> other navigation equipment on board) is legal as a "stand alone" for use
en
> route, terminal, and approach . (I know charts are still necessary.)
> Please advise.

The pressure altitude input and operator input baro correction, such as the
new UPSAT unit, will be a requirement for "sole means".

John P. Tarver, MS/PE

Fred E. Pate
September 25th 03, 04:42 AM
> GPS: TSO C129a, Class A1 (en route, terminal, and approach)

Yeah, your guess that he was referring to just the GPS portion is
correct. I've read about this "sole source" stuff in a number of places.
A non-WAAS reciever, as the 430s currently are, cannot be used as
"sole source" for anything except GPS approaches. Say, for instance,
that you're cleared along an airway. If so, you have to have a working
VOR reciever available and the VORs that define that airway have to be
operational (its in AIM 1-1-21). But, as you say, the 430 has a VOR
reciever, so you're okay (the 400, however, doesn't; it is just a GPS).
Maybe that's why airways aren't in the 430's database.

Now, if you don't intend on ever using VORs, you don't need a VOR
reciever, right? At least not outside of Class B airspace. In fact
where does it say that you need anything more than a wet compass and a
clock? And, if you can be legal with just a compass and a clock,
certainly you can't become illegal if you add an IFR GPS, right? So
what the hell does it mean, this "sole source" thing anyway?

Peter

Tarver Engineering
September 25th 03, 02:49 PM
"Fred E. Pate" > wrote in message
...
>
> > GPS: TSO C129a, Class A1 (en route, terminal, and approach)
>
> Yeah, your guess that he was referring to just the GPS portion is
> correct. I've read about this "sole source" stuff in a number of places.
> A non-WAAS reciever, as the 430s currently are, cannot be used as
> "sole source" for anything except GPS approaches.

No, a 430 does not have accurate enough an altitude datum to be sole means.
Altitude is the first portion of WAAS to turn out to be a bust.

PaulaJay1
September 27th 03, 12:39 AM
In article >, "Ron Natalie"
> writes:

>Since the Garmin 430 contains not only TSO'd
>> GPS but also VOR, LOC, GS, etc., my position is that this unit (without any
>> other navigation equipment on board) is legal as a "stand alone" for use en
>> route, terminal, and approach
>
>Yep. As a matter of fact, many new aircraft are delivered with only
>430/530's
>as nav equipement.

A single 430 should not be used with the Idea that a VOR will always be
available if the GPS goes south. I had the display in my 430 fail which made
the COMPLETE unit inop.( unless you knew where the com was and could count the
clicks :-) )

Chuck

Ron Natalie
September 27th 03, 04:33 PM
"PaulaJay1" > wrote in message ...
>
> A single 430 should not be used with the Idea that a VOR will always be
> available if the GPS goes south. I had the display in my 430 fail which made
> the COMPLETE unit inop.( unless you knew where the com was and could count the
> clicks :-) )
>
That redundancy concern is different from the legal issues. It's perfectly legal
to fly (subject to the ground facilities needed) with a single NAVCOM. It can
just as easily go TU leaving you with no nav or com.

The regulations just say that if you are going to use GPS that your alternate requirements
have to be met without using GPS. They're figuring satellite geometry failure (GPS system)
not the reliablity of the box installed.

Fred E. Pate
September 28th 03, 04:37 AM
Tarver Engineering wrote:
> "Fred E. Pate" > wrote in message
> ...
>
>>>GPS: TSO C129a, Class A1 (en route, terminal, and approach)
>>
>>Yeah, your guess that he was referring to just the GPS portion is
>>correct. I've read about this "sole source" stuff in a number of places.
>> A non-WAAS reciever, as the 430s currently are, cannot be used as
>>"sole source" for anything except GPS approaches.
>
>
> No, a 430 does not have accurate enough an altitude datum to be sole means.
> Altitude is the first portion of WAAS to turn out to be a bust.
>

Well, I don't think "sole source" is that restrictive. A VOR reciever
is approved as a "sole source" of navigation. You still need an
altimeter. "Sole source" just refers to horizontal navigation. All GPS
approaches are currently non-precision: no vertical guidance.

Fred E. Pate
September 28th 03, 04:45 AM
Ron Natalie wrote:
> The regulations just say that if you are going to use GPS that your alternate requirements
> have to be met without using GPS. They're figuring satellite geometry failure (GPS system)
> not the reliablity of the box installed.

Which is more likely though? I guess, by induction or extrapolation or
whatever, that the FAA figures ATC can handle one guy having a bad day
at a time (if his GPS/NAV box fails) and not half the airplanes all at
once (widespread GPS jamming or satellite system failure).

Tarver Engineering
September 28th 03, 03:59 PM
"Fred E. Pate" > wrote in message
...
> Tarver Engineering wrote:
> > "Fred E. Pate" > wrote in message
> > ...
> >
> >>>GPS: TSO C129a, Class A1 (en route, terminal, and approach)
> >>
> >>Yeah, your guess that he was referring to just the GPS portion is
> >>correct. I've read about this "sole source" stuff in a number of places.
> >> A non-WAAS reciever, as the 430s currently are, cannot be used as
> >>"sole source" for anything except GPS approaches.
> >
> >
> > No, a 430 does not have accurate enough an altitude datum to be sole
means.
> > Altitude is the first portion of WAAS to turn out to be a bust.
> >
>
> Well, I don't think "sole source" is that restrictive. A VOR reciever
> is approved as a "sole source" of navigation. You still need an
> altimeter. "Sole source" just refers to horizontal navigation. All GPS
> approaches are currently non-precision: no vertical guidance.

I do not believe "sole source" is regulatory. You may as well use the term
"eanie beanie".

Fred E. Pate
September 29th 03, 07:55 AM
Tarver Engineering wrote:

>
> I do not believe "sole source" is regulatory. You may as well use the term
> "eanie beanie".
>

Sounds good to me. "Not approved for eanie-beanie navigation without an
upgrade."

Ron Natalie
September 29th 03, 03:40 PM
"Fred E. Pate" > wrote in message ...
> Ron Natalie wrote:
> > The regulations just say that if you are going to use GPS that your alternate requirements
> > have to be met without using GPS. They're figuring satellite geometry failure (GPS system)
> > not the reliablity of the box installed.
>
> Which is more likely though? I guess, by induction or extrapolation or
> whatever, that the FAA figures ATC can handle one guy having a bad day
> at a time (if his GPS/NAV box fails) and not half the airplanes all at
> once (widespread GPS jamming or satellite system failure).

Depends on who made your equipment :-)

But the issue is, that they were concerned about GPS signal reliability NOT the
reliability of any single manufacturer's unit by this requirement.

Tarver Engineering
September 29th 03, 03:58 PM
"Fred E. Pate" > wrote in message
...
> Tarver Engineering wrote:
>
> >
> > I do not believe "sole source" is regulatory. You may as well use the
term
> > "eanie beanie".
> >
>
> Sounds good to me. "Not approved for eanie-beanie navigation without an
> upgrade."

I wonder if Garman will offer an upgrade. Since they bought UPSat, there
seems to be a tendancy to orphan GPS systems.

Richard
September 29th 03, 08:29 PM
Thanks to everyone who contributed to this discussion. Special thanks to
those who actually answered my question!

"Richard" > wrote in message
t...
> Probably this has been answered in this forum previously, but I can't find
> it. Sorry.
>
> I recently got into a friendly discussion with a knowledgable CFII who
said
> a Garmin 430 could not be legally used as "sole means of navigation".
> Looking back, I think what he means is that "GPS" (even IFR certified
units)
> can not be used as sole means. Since the Garmin 430 contains not only
TSO'd
> GPS but also VOR, LOC, GS, etc., my position is that this unit (without
any
> other navigation equipment on board) is legal as a "stand alone" for use
en
> route, terminal, and approach . (I know charts are still necessary.)
> Please advise.
>
> The following came off the Garmin web site:
> ******************
> GPS: TSO C129a, Class A1 (en route, terminal, and approach)
>
> VOR: TSO C40c
>
> LOC: TSO C36e
>
> GS: TSO C34e
>
> VHF COM: TSO C37d, Class 4 and 6 (transmit) and TSO C38d, Class C and E
> (receiver)
>
> The GNS 430 is the most versatile panel-mounted product GARMIN has
produced
> to date. It combines GPS navigation, VHF communication, and moving map
> graphics on a big color display. This "all in one box" 12-channel unit
> offers IFR GPS, ILS, VOR, LOC and glideslope capability in a single,
> space-saving package
>
> **************************
>
>
>
>
>
>
>

September 30th 03, 08:27 AM
Tarver Engineering wrote:

>
>I wonder if Garman will offer an upgrade. Since they bought UPSat, there
>seems to be a tendancy to orphan GPS systems.
>
>

they've already committed to a WAAS upgrade for their GNS 430/530 boxes.

Tarver Engineering
September 30th 03, 02:13 PM
> wrote in message ...
> Tarver Engineering wrote:
>
> >
> >I wonder if Garman will offer an upgrade. Since they bought UPSat, there
> >seems to be a tendancy to orphan GPS systems.
> >
> >
>
> they've already committed to a WAAS upgrade for their GNS 430/530 boxes.

WAAS alone doesn't get you anything.

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