There are just to many factors you do not controll, especially if you fly close to terrain. That tree that was upright yesterday, might have dropped. The bird

There are just to many factors you do not controll, especially if you fly close to terrain. That tree that was upright yesterday, might have dropped. The birds that where far away in the morning, might get in your way. The little pond on the way, that was just mud, is dryed dust today swirling up. Wind drafts coming and going.