As for flight paths and what Appears to be the silly way for a ball earth but makes sense for a flat earth, it reminds me of the child quiz. There is a spider in the corner of the room on the floor and he wants to get to the opp corner on the ceiling. Which is the quickest path? We instantly say, across the floor and up the wall join. BUT, if we flatten the room we then draw a straight line, we find the quickest path is diagonally up one wall and then diagonally across the ceiling, which Looks longer but is best.
The flat earth movement began in the 19th century with the publications of Samuel Rowbotham. In the summer of 1838, Rowbotham conducted his Bedford level experiment. The Bedford level is a six-mile stretch of water that is very straight and level. Over the six miles, the earth ought to curve downward by 24 feet. Rowbotham stationed himself at one end of the Bedford level, and arranged for someone else in a small boat to row to the other end. A five-foot mast was attached to the boat, so certainly by the end of the level the mast would not be visible, because the top of the mast would have been 11 feet below Rowbotham’s line of sight. Rowbotham observed the boat with a telescope mounted eight inches above the water. Rowbotham could see the small boat over the entire course of the Bedford level, whereupon he became convinced that the earth was flat. I’ve previously discussed the Bedford level experiment, in which I explained that atmospheric refraction bent the light of the boat along the surface of the earth, making the boat visible, even though the boat actually was below the direct line of sight. Here I wish to expand upon the phenomenon that caused Rowbotham’s experiment to go awry.

95) On a clear day from the highland near Douglas Harbor on the Isle of Man, the whole length of the coast of North Wales is often plainly visible to the naked eye. From the Point of Ayr at the mouth of the River Dee to Holyhead comprises a 50 mile stretch which has also been repeatedly found to be perfectly horizontal. If the Earth actually had curvature of 8 inches per mile squared, as NASA and modern astronomy claim, the 50 mile length of Welsh coast seen along the horizon in Liverpool Bay would have to decline from the center-point an easily detectable 416 feet on each side!
"Yes, but we can circumnavigate the South easily enough," is often said by those who don't know, The British Ship Challenger recently completed the circuit of the Southern region - indirectly, to be sure - but she was three years about it, and traversed nearly 69,000 miles - a stretch long enough to have taken her six times round on the globular hypothesis. This is a proof that Earth is not a globe.
113) The idea that people are standing, ships are sailing and planes are flying upside down on certain parts of Earth while others tilted at 90 degrees and all other impossible angles is complete absurdity. The idea that a man digging a hole straight down could eventually reach sky on the other side is ludicrous. Common sense tells every free-thinking person correctly that there truly is an “up” and “down” in nature, unlike the “everything is relative” rhetoric of the Newtonian/Einsteinian paradigm.
Astronomers tell us that, in consequence of the Earth's "rotundity," the perpendicular walls of buildings are, nowhere, parallel, and that even the walls of houses on opposite sides of a street are not! But, since all observation fails to find any evidence of this want of parallelism which theory demands, the idea must be renounced as being absurd and in opposition to all well-known facts. This is a proof that the Earth is not a globe.