Basic Flying Rule: "Try to stay in the middle of the air. Do not go near the edges of it. The edges of the air can be recognized by the appearance of ground, buildings, sea, trees and interstellar space. It is much more difficult to fly there."
"Home is behind, the world ahead, and there are many paths to tread Through shadows to the edge of night, until the stars are all alight." - J.R.R. Tolkien, "A Walking Song"