Parallel Track function in GPS?

Final sentence should read:

than issuing parallel *offset* tracks in a non-radar environment.

No doubt about its usefulness in areas with limited, or no, radar coverage.
But, I doubt that offset tracks would do much good there. Where the terrain
environment would permit parallel tracks, the publication of parallel tracks
as separate database routes would probably be much safer than issuing
parallel offset tracks in a non-radar environment.

The push for lateral offsets is greatest for non-radar environments, where
controllers are less likely to catch an operational error that puts two planes
on the same track and altitude. As I stated in an earlier post, one of the
proposed criteria is that the use of lateral offsets be transparent to the
controller. So offsets will probably be implemented as procedural changes
(for example, always fly 1 NM to the right of centerline if able), not as
clearances.

Barry wrote:

No doubt about its usefulness in areas with limited, or no, radar coverage.
But, I doubt that offset tracks would do much good there. Where the terrain
environment would permit parallel tracks, the publication of parallel tracks
as separate database routes would probably be much safer than issuing
parallel offset tracks in a non-radar environment.

I doubt the industry will buy into that. Too many opportunities for errors.
Plus, the parallel track has to have the same obstacle assessment as the "primary"
track, so it would be better to have them published and in the database; i.e.,
Track Bishop Alpha, Track Bishop Bravo, etc.

wrote in message ...


Bob Noel wrote:


Not much use yet, other than oceanic routes, I guess. But the theory
is that it will be used in RNP airspace.

That is a major disconnect between avionics engineers who dream of selling
more and more equipment and of an ATC system driven by radar separation
and
navigation. And, the radar isn't getting any better with some limited
terminal exceptions.

The Greens won't let us pour concrete, so what is the alternative?
1) restrict small GA access
2) ...

Barry wrote in message
news
Is "fly parallel to V157 offset 2 miles to the left" something
that I might ever expect to get in an IFR clearance if I file /G ?

One of the concerns with GPS is that the great accuracy can sometimes
increase
the probability of a midair collision compared to conventional nav.
Consider
two aircraft traveling on the same route in opposite directions at
different
altitudes, in non-radar airspace. If, due to a pilot or controller
error,
both planes end up at the same altitude, the probability that they
would hit
was quite small with VOR, but much higher with GPS. Some airline
pilots have
already started flying lateral offsets on their own, and ICAO is
studying the
issue and trying to come up with standards. One of the proposed
criteria is
that the procedure be transparent to the controllers. So it's
unlikely that
ATC will ever assign a clearance to fly an offset, but at some point
pilots
might be permitted or required to fly an offset on some routes.


This FMS/GPS-assisted mid-air risk is what I have seen discussed in
numerous big-iron forums and an ALPA magazine. In both places the
discussion seemed to favor a small offset, say 1 mile right of
centerline, to avoid nose to nose meetings.

--
Scott

Roy Smith wrote:
Yesterday I played with the parallel track function in the CNX-80 for
But, here's my question. Why is it in the box to begin with? Other
than the gee-wiz marketing value, is there any real practical reason for
it existing?

We use it for search and rescue in Civil Air Patrol. Not only is
there parallel track in some of the boxes, some of the Garmins have
the ability to turn on the CAP grid system "overlay", so that one can
see (within the accuracy of GPS) that you are inside or outside of a
particular grid, and turning on the "bread crumbs", you can even see
how accurately you flew the grid and if you covered it all.

Best regards,

LtCol Jer/ Eberhard, Colorado Wing Checkpilot (airplanes and gliders)

--
LtCol Jer/ Eberhard, CO-Wing, Thompson Valley CS., Ft Collins, CO
CELL/VM: 970 231-6325, CELL Message: 9702316325'at'mobile.att.net
EMAIL: jer'at'frii.com WEB: http://www.frii.net/~jer
C-206 N9513G, CFII Airplane&Glider, FAA-DEN Aviation Safety Counselor
CAP-CO Mission&Aircraft CheckPilot, BM218 HAM N0FZD, 197 Young Eagles!