Lowest Cost GPS IFR system?

On 11/18/05 4:28 PM, in article , "tom
pettit peakorg" tompetatdot wrote:

I'm currently flying VFR in a vfr equipped plane. What would be the lowest
cost GPS based instrument system I could install and be legal for IFR
flying?

I looked through the last six months of this newsgroup, but didn't see a FAQ
or the answer to the above, so I hope it won't be something that was just
hashed out.

thanks,
tom pettit


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On 11/18/2005 3:43 PM, tom pettit tompetatpeak wrote:
I don't currently have any navigation equipment. I was hoping that a
single, certified, gps unit could be used as primary, with an uncertified
unit as back up. I was hoping I didn't need anything else. Reading the
FARS it isn't very specific, or more likely, I just don't know enough about
this stuff yet.
thanks,
tom

Well, start with FAR 91.205. Specifically, 91.205 (d), and
91.205 (d) (2), where it state:

"...navigational equipment appropriate to the ground
facilities to be used".

Then, have a look at the AIM, in the section on Navigational Aids (section
1), specifically, 1-1-19 (d) (1), which talks about Authorization to conduct
any GPS operation under IFR, and later it talks about the requirements
for alternate navigation equipment.


Basically, what this all boils down to, is this: If you have a
IFR-certified GPS system (TSO-129 certified), like the Garmin
GNS 430, you can use it for IFR operations, but the plane needs
to be equipped with the typical IFR navigation radios anyway.

There are some exceptions, but this should get you thinking in the
right direction. I would expect that the GPS systems that can be
used without any other nav equipment on board would be more expensive
than a TSO-129 system + standard nav gear anyway.

I hope this helps,


"Mark Hansen" wrote in message
...
On 11/18/2005 13:28, tom pettit tompetatpeak wrote:

I'm currently flying VFR in a vfr equipped plane. What would be the
lowest cost GPS based instrument system I could install and be legal for
IFR flying?

I looked through the last six months of this newsgroup, but didn't see a
FAQ or the answer to the above, so I hope it won't be something that was
just hashed out.

thanks,
tom pettit

Keep in mind that it takes a specific unit (a TSO one forty something
rather than the TSO 129... I'm not sure I have those number correct) for
the GPS unit to be used as the sole means of IFR navigation.

I mention this, because you said your plane is not currently IFR
capable. In order to use one of the TSO 129 certified GPS units for
IFR flight, the plane must still have the navigation equipment on
board for the ground based navigation aids along the route of flight.

Does any of this apply to you?

If not, sorry if I misunderstood your situation.


--
Mark Hansen, PP-ASEL, Instrument Airplane
Sacramento, CA




--
Mark Hansen, PP-ASEL, Instrument Airplane
Sacramento, CA

Robert M. Gary wrote:
Since the bulk of the cost is installation the actual GPS unit you
select will not have a dramatic effect on end price. A GNS430 is about
$11,000 installed here. Any other GPS is + or - $1000 or so.

Not necessarily. The GX55 I had in my 182 and now in the Bonanza costs
nothing to install if you replaced a loran in the process and the loran
antenna was on top of the fuselage. The expense will be in getting it
legal for IFR. An terminal/enroute only box costs far less to get legal
than an approach box.

Tom,
Used Bendix King, Apollo, Or even Northstar if you can find it.
Like others have said the cost for installation is significant.
I installed a KLN-90B 10 years ago. At the time it had the most bells
and whistles out there and was the easiest to use. It was also the most
expensive. By today's standards it is dog meat. It has over 1000 hours
on it without a problem. Solid, reliable. You will also need a display
for annunciation's and a deviation indicator.
I chose an HSI switched between NAV 1 and the GPS. That lasted for 9
years and then I replaced it with and updated one.
Michelle

tom pettit tompetatpeak wrote:

I'm currently flying VFR in a vfr equipped plane. What would be the lowest
cost GPS based instrument system I could install and be legal for IFR
flying?

I looked through the last six months of this newsgroup, but didn't see a FAQ
or the answer to the above, so I hope it won't be something that was just
hashed out.

thanks,
tom pettit

So how come I can't just use the gps alone? It seems like it is much more
flexible, and then I wouldn't be as dependent on what ground based stuff was
available.
tom

Basically, what this all boils down to, is this: If you have a
IFR-certified GPS system (TSO-129 certified), like the Garmin
GNS 430, you can use it for IFR operations, but the plane needs
to be equipped with the typical IFR navigation radios anyway.

Because a GPS failure or outage can affect an entire REGION, while if a
single ground based navaid goes on the fritz, other stuff nearby will
likely still work.

Truth is, right now, the best approach minimums are with ground based
ILS equipment. Unless you have baro-VNAV capability (which is not in the
cheaper GPS equipment) the GPS approach may leave you in the clouds
while the "antiquated" precision approach equipment can get you to 200
feet and a mile.

Get some instrument training.. not the whole rating.. but some.. and see
what is out there. (I am presuming you dont have one, but that is just a
hunch)

Also, if you dont have a rating yet, and plan to train in your own
plane, you will need to be equipped for the checkride to perform 1 type
of precision approach and 2 types of non-precision approaches (unless
things have changed and I missed the memo). Having a "cheap ifr GPS" may
not even have approach capability. Those that currently do are likely
only LNAV (no glideslope, thus non-precision approach). Unless you have
a Precision Approach Radar site, or a VNAV (baro aided or WAAS) you will
need an ILS to meet the checkride requirements in that plane


Dave

tom pettit peak wrote:
So how come I can't just use the gps alone? It seems like it is much more
flexible, and then I wouldn't be as dependent on what ground based stuff was
available.
tom


Basically, what this all boils down to, is this: If you have a
IFR-certified GPS system (TSO-129 certified), like the Garmin
GNS 430, you can use it for IFR operations, but the plane needs
to be equipped with the typical IFR navigation radios anyway.

[quote=tom pettit]So how come I can't just use the gps alone? It seems like it is much more
flexible, and then I wouldn't be as dependent on what ground based stuff was
available.
tom

-------------------------

you can do that - but forget about saving money. you would need the garmin 480 GPS which can be used as a sole-means-of-navigation device. be ready to fork out at least $15,000 by the time it's installed with all the required hardware and config though.

as per others on this thread, i question the wisdom of relying only on a GPS - for example, last time as i passed through richmond (KRIC) a notam said GPS signal may or may not be adequate for navigation. and just like the NOTAM said, we got a RAIM alert just before passing the FAF.

another time in albukerque, we were on final descent, navigating by GPS at night when the unit went dead (welll, not dead, but it gave a message of "no signal" or something similar). turns out there were some military exercises going on in the area that included jamming the GPS signal. that final leg made for some interesting scrambling in the cockpit looking for maps, beacons and frequencies to navigate "a la VHF" before we sailed past where we were going...

:-)

francois

"tom pettit" tompetatpeakdotorg wrote:

So how come I can't just use the gps alone? It seems like it is much more
flexible, and then I wouldn't be as dependent on what ground based stuff was
available.
tom

Your alternate must have a non-GPS approach (unless you use WAAS).

VORs and ILS will be here forever.

Ron Lee

The problem with the less expensive unit is that they require more
external hardware to install. The more expensive units (GNS530, etc)
are "all in one" IFR units. WIth the GX55 you need to install a remote
head, a remote signal light etc. When you're paying $120/hr for
avionics labor, it gets expensive real quick,

While there are numerous used boxes out there at low prices, you have to
consider that the installation is a big part of the total cost. Another
consideration is that the newer systems have more intuitive operating logic.
The newer systems (430/530/480) all incorporate com and VLOC/GS. The older
units required more wiring and usually a switch/annunciator box which drives
up the cost. The new integrated avionics are also lighter. I removed 11lb
by installing a 530/300XL instead of a 300XL/155 with all its switching
boxes and VLOC converter strung together with miles of wire. .

I did the avionics installation myself on my Helio. A picture of the Helio
panel is on Jay Honecks site
http://alexisparkinn.com/photogaller...295H_Panel.jpg. Before
starting, you need to be sure that someone will sign off the installation
when you are done! It took a while because I was always waiting for more of
some wire or connector but it worked perfectly from the beginning. The
tools are often availible on ebay.

Mike
MU-2


"tom pettit peak org" tompetatdot wrote in message
...
I'm currently flying VFR in a vfr equipped plane. What would be the
lowest cost GPS based instrument system I could install and be legal for
IFR flying?

I looked through the last six months of this newsgroup, but didn't see a
FAQ or the answer to the above, so I hope it won't be something that was
just hashed out.

thanks,
tom pettit