The flight paths are displayed on a flat map. The Earth could be any shape and this flat map is just a convenience, so it really is not proof one way or the other for the shape of the Earth. We are just supposed to take their word that the flat map represents a round world. Do you see my point now?
Just a few passing remarks before shutting down for the night.:
1.On any other place than this forum it would be "common knowledge" that all flat maps are made from various projections of a globe - or in the Flat Earth reference a "Round Earth." Depending on how many "9's" you put after the decimal point you put after it 99.99999999999 % of the world knows this to be true. There is no question of the accuracy of flight paths in the real world.For example, FAA Sectional Charts are made from segments from a Round Earth and are limited in area to minimize any distortion.
2. For example.:How could you possibly make an accurate map of a flight path in the southern hemisphere from the so-called "Unipolar Flat Earth Map ?" Or for that matter the "Bi Polar" or "Antarctica as a Continent" map ? If you were to make a Sectional Chart for flight paths in Australia from the flat earth map of the world for example it would have all the distortions as in the flat earth map of the world.
3.Can you explain why the so-called Flat Earth Map is or is not simply a map made by one method of a projection from a gobe or "Round Earth ?"
4.jroa : By your signature line would that be inferring that the mentality level of Flat Earthers is second grade level ?
My apologies for intruding on this website. My excuse is that I am simply too much of a realist who works in the real world.
jroa If you ever get around to it, could you at least give me an answer to my question #4 ?
Answers to numbers 1, 2 and 3 would also be appreciated. 
Googleotomy, I suppose it is not a good signature, seeing as the meaning is not self evident. However, it is meant to be a light hearted signature, not a serious one.
The reasons I believed it to be humorous are the following:
1. The signature offers a matter-of-fact answer without any substantiating proof, which is something that RE'ers often claim FE'ers are guilty of.
2. It is written in a condescending manner, treating the reader as if he/she is in second grade or just a child.
3. It is a parody on the childhood indoctrination that is sometimes claimed about RE'ers. In other words, children believe what they are taught in school without questioning it and grow up to be adults who then believe it is all indisputable facts.
When I think of a better signature, I will change it.