IFR with a VFR GPS

Gerald Sylvester wrote:

my handheld keeps updating and displaying as though I kept going
straight ahead at the same exact speed and course as when it
lost the lock. So there is NO warning at all.

Gerald

I've owned three Garmin hand-helds, 195, 295, and 296. They all make it
very apparent when GPS is lost.

Gerald Sylvester wrote:


that's exactly why there are IFR-certified GPS's that must adhere to
some basic design, operating principles and functionability
and then there are 'other' GPS's. There
is no such thing as a 'VFR GPS.' It is just an 'other' GPS. It could
be a Garmin Forerunner to a Garmin 396. As long as it is not certified,
who knows where it falls between those. Now we all know the 396 is
on the same level as a IFR-certified GPS but all those others leave
a LOT of room for interpretation in the design none of which the user
has access to (manufacturer proprietary).

Gerald


The 396 is really a 296 with a datalink for weather. I have a 195 I
still use for desktop procedures work, because it is the only Garmin
that provides NMEA statements in simulator mode.

I then had a 295, which I gifted to a pilot friend when I got my 296
this past Spring.

Both the 195 and 295 have slow, clunky processors. The 296, however, is
awesome. With a roof-mount antenna I would be very comfortable
"cheating" with a 296. ;-) The terrain feature alone is fantastic.
It's not full-press EGPWS, but close enough for light aircraft ops.

I work with this stuff all the time, especially with criteria and the
new advanced RNP stuff.

I may be a bad boy, but I have no doubt the 296 will do as good as a
Garmin 500 series for a conventional RNAV IAP provided I built the
approach as a flight plan before I launch. In that sense it is limited;
i.e., I wouldn't want to be faced with that task in the air.

Ron Lee wrote:



Yes there is. RAIM provided integrity. As long as no signal error
exists (vast majority of the time) then your assertion is basically
correct.

Ron Lee

If I have my Garmin 296 on a roof mount antenna and I check its distance
to a VOR station against my DME, then do an IAP within 30 minutes, or
so, of that check with 6, or more satellites in view, I have essentially
as much integrity as an IFR box with RAIM.

wrote:

Yes there is. RAIM provided integrity. As long as no signal error
exists (vast majority of the time) then your assertion is basically
correct.

Ron Lee

If I have my Garmin 296 on a roof mount antenna and I check its distance
to a VOR station against my DME, then do an IAP within 30 minutes, or
so, of that check with 6, or more satellites in view, I have essentially
as much integrity as an IFR box with RAIM.

That is incorrect. You have no assurance that there was not a signal
failure in that 30 minutes. The odds are in your favor but in no way
do you have the same integrity protection as an IFR GPS unit.

Ron Lee

Ron Lee wrote:
wrote:


Yes there is. RAIM provided integrity. As long as no signal error
exists (vast majority of the time) then your assertion is basically
correct.

Ron Lee

If I have my Garmin 296 on a roof mount antenna and I check its distance
to a VOR station against my DME, then do an IAP within 30 minutes, or
so, of that check with 6, or more satellites in view, I have essentially
as much integrity as an IFR box with RAIM.


That is incorrect. You have no assurance that there was not a signal
failure in that 30 minutes. The odds are in your favor but in no way
do you have the same integrity protection as an IFR GPS unit.

Ron Lee

The odds are overwhelmingly in my favor, certainly much more so than
using ADF for an IAP, or even VOR at distances near system limits.

Ron Lee wrote:
"Stan Prevost" wrote:

That seems to be an overly broad statement. I have put "VFR GPS" in Remarks
when filing /U for an off-airways (random) route and had controllers
specifically refer to using my VFR GPS to proceed direct to an intersection.
Whether they should have done so is another issue. But is sure seemed to
make a difference.


Your non-IFR GPS has intersections in it? What model is it?

Ron Lee

Every Garmin handheld I have owned, 195, 295, and 296, have a complete
Americas Jeppesen LNAV database; all intersections, waypoints, airports,
runway layout for IFR airports, all communications and nav frequencies,
distance to FAA transmitter, and so forth.

The approach is abbreviated but all the fixes are in the database to
build the complete approach as a flight plan.

The terrain database of the 296 is essentially the same as any
full-press EGPWS I have used. It just doesn't have the aural warnings.

Gerald Sylvester wrote:

Vintage Garmin 195, updated software and database, has them, and
approaches as well.



when was the last time you updated the database?

Gerald

I updated my 195 this past June. It has everything so far as I can
determine. They had to update the firmware a couple, or so, years ago
to handle the ever increasing Jeppesen nav databast.

: indeed - in addition, the capstone project (ADS-B) in Alaska (used
: prominently by commercial ops) requires GPS data to operate.

I recall after moving to Juneau in 1992 that the local news was touting AK
airlines as being the first to test the GPS approaches. Didn't understand really what
that meant at the time, but given the weather there and the huge percentage of missed
approaches, I can understand why it made financial sense to blaze trail. It is truly
about the worst kind of terrain and weather available.

First time I flew it was two years ago. I expected to be coming in from the
west as always, but nothing looked right back in the passenger compartment when we
finally broke out at about 400' AGL/MSL.... including what seemed like a 30 degree
bank! Anyway, impressive when one's not expecting it.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

I'm glad I wasn't drinking anything when I read that. Hilarious.

To bring it back on topic, basically Mr. McNicoll does not think the
requirements of the TSO pertaining to enroute IFR navigation adds to the
safety of the flight. One of the things I like about aviation is that most
everything in the regs (notice I stated MOST and not ALL) has a good reason
behind it. As with regulations in general, a good part of the stipulations
will not apply to the majority of the situations. As a result, many folks
think they're "idiotic."

I see it simply as part of the attitude of "I've done it a hundred times
before so it's perfectly safe."

Marco Leon

"Peter R." wrote in message
...

Don't try to kiss and make up. We need time apart.

--
Peter
If you love someone, set him free.























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"Marco Leon" mmleon(at)yahoo.com wrote in message
...

To bring it back on topic, basically Mr. McNicoll does not think the
requirements of the TSO pertaining to enroute IFR navigation adds to the
safety of the flight. One of the things I like about aviation is that most
everything in the regs (notice I stated MOST and not ALL) has a good
reason
behind it. As with regulations in general, a good part of the stipulations
will not apply to the majority of the situations. As a result, many folks
think they're "idiotic."

I see it simply as part of the attitude of "I've done it a hundred times
before so it's perfectly safe."


Do you see any hazard in the use of a handheld GPS during enroute IFR
flight?