I don't think you're understanding what I'm saying.
you can only see so far in every direction, due to the atmosphere becoming too thick, and distorting your view.
If he's in a concord, he can see a circular field of vision, which fades of evenly in every direction, due to being surrounded by air/atmosphere. Obviously he can see the ground, as it's closer to him than the horizon (by horizon i mean the point which he can no longer differentiate between land and air).
if he's inside a plane, his view is restricted to that window. There are walls on either side, and he's not necessarily able to view from other windows, so he would not observe a circular field of vision. He would observe the ground being clear, until the horizon (remember my definition), which would be curved, due to it being the edge of his circular field of vision.
At ground level, as you said, there is much more atmosphere between you and another continent, whcih is why you are unable to view America from Australia etc.