odd nav happenings

[Guest almoto]

I don't know if anyone else hae seen this but i have notice that with the A340 if i am going gps direct from/to a few city pairs, dallas/rome, seattle/berlin,and Ksfo/egll the gps plot shows me off course and the map shows on course.any ideas?

[Bob Scott 7,721]

You will see that if you select direct point-to-point routings at distances greater than ~600nm. The GPS does not display the true great-circle route, which will be a curved line on any of the flat map projections (i.e. Mercator, Lambert etc). You will see a divergence from a straight-line as plotted on a flat projection until mid-course, then convergence back to the (incorrectly) plotted course.To avoid this, don't use such long direct routings...instead place waypoints at least every 600nm or so. In r/w ops, you generally need fixes every 400-500 nm if for no other reason than to provide hourly reporting fixes for the OCA.RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Washington, DC

[Guest almoto]

Ahh that's 'plains alot thanks