"Icebound" wrote in message
...
[...]
...so is there anything in the current crop of GPS and/or Autopilot
systems that allow me to maintain a small cross-track error of my
choosing, without actually entering off-navaid-off-airport waypoints?
...or do we care; am I overly concerned?

You are not overly concerned, it does present a greater chance of a
collision.

I haven't heard of a GPS unit that allows the user to set some sort of
"offset" from a course to follow, but it wouldn't surprise if such a feature
did exist somewhere.

Beyond that, the "big sky theory" still works reasonably well. Two
airplanes in level flight on opposite headings on the same airway stand a
decently improved chance of running into each other if they are using GPS.
But when at least one is climbing, they share their altitude for such a
short period of time, I would think that the *actual* risk is relatively
low, even if the GPS does significantly increase the risk when compared to a
VOR receiver.

In any case, even before GPS it was still reasonably important to be alert
for other traffic while traveling on airways (even beyond the general
importance of doing so at all times). GPS increases the risk, but the risk
was always there and I've certainly had my share of close encounters (under
1 mile) flying on airways with a VOR receiver.

Pete