First, great job, and kudos for creating a freeware tool.

Second, some noobish questions (sorry)... how accurate is the route? I live near BUD and each time I fly FRA-BUD, the plane lands in the SE-NW direction, so first it goes a bit futher than BUD, than turns a 180° and lands. This is absent on your map. Is it intentional?

Also, do you calculate the route with a computer or there's some official route plan for the flights? Do you have data on the planned flight altitude of the flights as well?