GNS430 on the Airway

Matt Barrow wrote:

"Ron Lee" wrote in message
...

"Ted" wrote:


wrote...

Matt Barrow wrote:

Hmmm...how are they going to route traffic when all the VOR's are
decommissioned in the next few years?

Who told you that?

http://www.faa.gov/asd/gpstrans.pdf

http://avnwww.jccbi.gov/icasc/PDF/frp1999.pdf

http://www.alaska.faa.gov/capstone/d...de%20v1.1H.pdf

Don't use outdated FRPs.


Do you have a newer version?


The FAAs OLD thought of getting rid of all
ground-based navaids in favor of SATNAV was flawed from the beginning.
It was further reduced to outdated after 9/11.


How so?




There isn't a newer version because the FAA does not like to admit when
they do incorrect planning.

If those old documents were valid some VORs would already be shutdown.

Roy Smith wrote:

Peter Clark wrote:

Garmin doesn't care about airways and thinks they're obsolete in the
GPS direct world. They don't even have them in the G1000 system and
have said they aren't planning on adding it


Wow, that really blows my mind. They've got it in the 480 (via the
Apollo/UPSAT acquisition), and it's one of the best features of that box.
It's staggering that they left it out of the G1000.

Garmin may thing airways are obsolete, but nobody's told ATC about that
yet, at least not around where I fly.

The guy who runs the 400/500/1000 program has always been hard-over
against an airway database.

Ron Lee wrote:

"Marco Leon" mmleon(at)yahoo.com wrote:


So how far off an airway is an aircraft when they are following a GPS flight
plan with every intersection and VOR? Is there an article or study somewhere
that includes metrics to back it up? For example, "a non-WAAS GPS-derived
line direct btween two intersection xx miles away will differ from the
airway between those same two intersections by x.x statute miles." How do
the error allowances play into this?



Since unaugmented GPS (not using WAAS) is accurate to 10 meters or so
(plus/minus) and an airway is plus/minus four MILES (or is is two?)
the navigation source (GPS) is not a major error source.

Ron Lee

VOR airway's primary is plus/minues 4 to 51 miles, where it expands at
4.5 degrees. The secondary is an additional 2 miles, which expands at
6.7 degrees at 51 miles.

The issues with mag var and declination are easily absorbed by the huge
widths of the victor airway. The problem is airway course changes
between facilities. An autoload of the airway not only solves that
issue, it keeps everything "spot on" and has all the non-compulsory
reporting points loaded and ready, if needed.

Dave Butler wrote:

Mark Hansen wrote:


All the airway segments (that's what we're talking about, right?) that I
know of have a defined point at each end of the segment. There is one
and only one great circle route between those two points. It's the same
great circle whether you follow it with a GPS or a VOR receiver.

The charted airway mag bearing is the issue. It was developed from one
source and Garmin, et al, may or may not use the same source.

But, you're right, it's no big deal, unless the airway has an
intersection course change of some magnitude.

wrote:
The guy who runs the 400/500/1000 program has always been hard-over
against an airway database.

Does he say why?

"Matt Barrow" wrote in message
...

"Ron Lee" wrote in message
...
"Ted" wrote:


wrote...
Matt Barrow wrote:

Hmmm...how are they going to route traffic when all the VOR's are
decommissioned in the next few years?

Who told you that?

http://www.faa.gov/asd/gpstrans.pdf

http://avnwww.jccbi.gov/icasc/PDF/frp1999.pdf

http://www.alaska.faa.gov/capstone/d...de%20v1.1H.pdf

Don't use outdated FRPs.

Do you have a newer version?

The FAAs OLD thought of getting rid of all
ground-based navaids in favor of SATNAV was flawed from the beginning.
It was further reduced to outdated after 9/11.

How so?

The only issue (or flaw) that has come to my attention is the risk of radio
interference on the GPS civilian frequency. The replacement GPS satellites
are being designed with a second civilian frequency to address this problem.

http://www.dot.gov/affairs/1998/dot5598.htm

http://www.aero.org/news/newsitems/g...on-041398.html

http://geodesy.geology.ohio-state.ed...09/gpsfre.html

http://igscb.jpl.nasa.gov/mail/igsma.../msg00316.html

http://clinton6.nara.gov/1998/03/199...an-signal.html

Roy Smith wrote:
wrote:

The guy who runs the 400/500/1000 program has always been hard-over
against an airway database.


Does he say why?



Never had an opportunity to press him on the issue. But, I think Garmin
is innovative but also concerned about liability issues. Just today
ZDC issued the following NOTAM:


KZDC WASHINGTON (ARTCC), DC.

02/064 - PILOTS UTILIZING JEPPESEN NAVIGATION DATABASE SYSTEMS FILED
ON J79 SOUTHBOUND TO CHS ARE ADVISED THAT PROCESSING IS NOT CORRECT AND
MAY CAUSE THEM TO NAVIGATE ON A ROUTE DIFFERENT OTHER THAN J79,
PRIMARILY STARTING AT THE KATZN INTERSECTION. PILOT DEVIATIONS ARE
POSSIBLE DUE TO THE ROUTING ERRORS WIE UNTIL 16 MAR 23:59

ted wrote:



The only issue (or flaw) that has come to my attention is the risk of radio
interference on the GPS civilian frequency. The replacement GPS satellites
are being designed with a second civilian frequency to address this problem.

How long will that take to populate the entire constellation?

wrote in message news:Z_4Hf.33790$JT.747@fed1read06...
Matt Barrow wrote:

How so?




There isn't a newer version because the FAA does not like to admit when
they do incorrect planning.

If those old documents were valid some VORs would already be shutdown.

Though VORs have some use in the near term, I can't see them being viable
beyond a "few" years.