Funny

Ganked from metaquotes:

From NASA’s Guide to Civil­ian Heli­copter Safe­ty:

Basic Fly­ing Rules:

1. Try to stay in the mid­dle of the air.
2. Do not go near the edges of it.
3. 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.