A number of Flat Earthers insist on an unequivocal "Newton is wrong claim"!

Of course, Newton was not aware of the finite velocity of light and had no thought of any "speed limit".

So I do wonder how these clever Flat Earthers do "everyday" calculations involving gravity and dynamics.

For example.

What method would you use to calculate the path and landing point of an object dropped from an aircraft at an altitude of 1,000 m, flying horizontally at 100 m/s? (Slow plane!)

Let's keep it easy and neglect air resistance.

Are you going to:

1) stay true to your "Newton is wrong claim" and use a full Tensor Calculus approach to GR (don't forget the mass of the plane!),

2) compromise a little and say to yourself "it's only a little object and the plane is not all that heavy or fast" and use the Schwarzschild Metric or

3) go the whole hog and say to yourself "Old Isaac might have been wrong, but his theory gives answers that are 'good enough'."?

Of course, in Newton's Laws of Motion the error is only 1 part in 1 million for speeds below about 420,000 m/s.

In other words what methods are used in practical, real world calculations?