This assumes that average height continues increasing, which is not a given. The Dutch might represent the peak. They might not ever get taller. Americans might

This assumes that average height continues increasing, which is not a given. The Dutch might represent the peak. They might not ever get taller. Americans might never reach that height. I would also not assume that airplanes would become more accommodating to taller people. They certainly have not become more accommodating of fatter people despite a lot of movement in that direction.