What is Trip Planner and How Can I Use it?: AirTreks
Direct (non-stop) flights from Salt Lake City to Redmond - schedules - FlightsFrom.com
RouteFinder (free access area)
A Flight Plan In 10 Steps
VfrFlight - free VFR flight planner
Airline Route Mapper
How To Make Flight Maps - One Mile at a Time
Create Animated 3D Map Routes with This Easy After Effects Plugin
Interactive Google Maps based Great Circle Route mapper shows actual/ideal shipping and airline routes against a mercator projection. Southern California to Southern England example[1395x694]. Link inside. : r/MapPorn
VfrFlight - free VFR flight planner
Mission Planner Flight PLAN — Mission Planner documentation