Lots of big references, but frankly you don't know what your talking about. Planes fly at an absolute level, and before terrain- following radar, would not be able to follow the earts supposed curve.
Frankly, you do not know what you are talking about. Planes keep to altitude. Ask any pilot. Have you any idea how an aircraft flies? Terrain following radar is only necessary if a pilot needs to fly so low that he is unable to manually adjust for height variations. Otherwise, the control surfaces manage just fine.
Do you use any logic at all? In your scenario, no aircraft would be able to land without TFR. Since aircraft were flying well before radar was invented, you may wish to rethink your ridiculous statement.
Oh, in case you didn't know, and I'm sure that you do not, "altitude" is the height relative to the sea or the surface from which the measurement is taken. "Height" is taken from a particular point.