Everyone and especially Michael,
I believe that APM mission planner has an error in calculating flight plans in terms of correcting for longitudinal distances with respect to latitude. For instance, if you create north south flight lines in flight planner on the equator, the line spacing between lines will be correct. But as your flight plan moves off from the equator, the distance between divisions of longitude decreases, and I don't believe this is properly corrected for in 1.1.86 version of mission planner. A north south flight plan with 100m line spacing on the equator will be 100m, but in Fairbanks Alaska it will be 230 meters.