If the earth is a enclosed in a dome, then the entire system would be moving upwards at 9.8m/s2 , not just the ground itself. Flight mechanics would not change in the slightest.
While I do agree with the Flat Earth, a dome or UA, that is not a bad way of looking at it on a flat earth subject under an acceleration.
It fits with the accelerating "rocket" or "elevator" used in the explanations of Einstein's Equivalence Principle.
From anywhere within the "rocket", "elevator" or the "Flat Earth", you cannot tell the difference between
uniform gravity and acceleration.
I don't really know why I, a Globe supporter, am pushing for "Universal Acceleration" over "Denpressure"
because denpressure would be far easier to debunk, as it is a
completely impossible explanation of the effects of gravity.So, Flat Earthers, by all means, go for denpressure, suits me fine - but you'll need to take a leaf out of Sceppy's book and simply ignore all gas physics.