If Earth were not an oblate spheroid (which is the overwhelming, if not unanimous belief of the scientific community), planes would not be able to accurately gauge their location. The curvature of Earth is fundamentally crucial in plane GPS systems. If Earth were flat, GPS would be incredibly inaccurate, and planes would not reach their destination.
Incorrect. This is as biased and silly as the fellow who claimed GPS only works with satellites. Also, it does not constitute as evidence. You can not say "this would not work on a flat
Earth, because the Earth is round." You are self-validating, which is fallacious.
Further proof: objects at the equator are heavier than objects elsewhere on Earth. This would not make sense in a flat-earth model, therefore Earth is not flat.
Well, for one, RET claims you will weigh less at the equator, not more. Second, no, that doesn't really happen. "This object weighs 0.001 here than it does on the north pole!" is not valid in any way, shape, or form.