In article ,
(Paul Tomblin) wrote:

In a previous article, Kyler Laird said:
Anyone know for sure whether or not this is an accurate way of
depicting Great Circle paths in the conUS?

No. Straight lines on Lambert Conformal maps are not great circles. We
use it normally because within one section it doesn't make a huge
difference, but if you're crossing several, the errors add up.

You've got to go pretty big distances before GC errors start to become
significant. For example, to go from 38N/77W to 38N/122W (roughly
Washington, DC to San Francisco, CA), the rhumbline is 270 and the GC is
284. 14 degrees on a coast to coast trip. If you're flying it nonstop
in a jet, it makes sense to take that into account. For most of us
flying spam cans, we just can't fly long enough legs for it to become
significant.

I just tried another one. From 38N/77W to 38N/100W is just under 1100
nm, or about the limit for the longest legged GA airplane I know of.
Again, a rhumbline of 270, CG of 277 (7 degrees correction).

For most of us, CG routes are just not something to worry about.