If the Earth was really a sphere, helicopters would hover while the location came to them. In Round Earth Theory, the earth "spins" at 1000 miles per hour. In Round Earth Theory, a helicopter just could hover for 4 hours and a helicopter in New York would land in Utah.
Check out the link below from conspiracy science site "Astro-Society" claiming that the earth spins 1000 miles per hour.
https://astrosociety.org/edu/publications/tnl/71/howfast.html
Rather helicopters have to fly to their destination proving the Earth is flat.
Because the earth is flat, helicopter pilots have to constantly adjust their controls so as not to fly off into space.
If the Earth were really spinning, helicopters that hover would land hundreds of miles Westwards --- They Don't.