What is the most invisible obstacles to avoid and notice when flying a drone?

Question

Now I am understanding one thing: there are two kinds of obstacles, in addition to the visible obstacles, such as trees, there are also invisible obstacles that will affect the flight of the drone.

What invisible obstacles do you think need the most attention and avoid? And best practice advice on avoiding it and improving the safety of drone operations.

This is a meaningful question because the visible ones will be noticed and avoided easiler, but the invisible ones need to be discussed and made more clearly understood.

Answer 1

Overhead wires are probably the biggest issue. You really have to watch out for the poles and use them to ensure you're high enough to avoid the wires because you often won't see the wires until it's too late. You should be aware of any wires before you fly, and make sure you're aware of where they are at all times during the flight ("maintain situational awareness" in pilot-speak).

The one people talk about a lot is 'scraggle', or thin branches and twigs with no leaves. It's really only a problem if you're flying very close to trees and bushes. If you're trying to fly under a low branch, or through a gap in some trees, it's worth inspecting it first.

The other class of 'invisible' obstacle are those that are behind you and out of sight. These are the ones that usually catch beginners. Don't fly backwards or sideways unless you're absolutely sure it's empty space. It's safest to keep moving forwards, as the wind could be carrying you backwards.