flying stone?

[bosun]

Is flying stone has any special meaning?

for exmple, i found this expression while reading a short ariticle.
... laer they realize that they are not just a flying stone. they realize that they are like a bird- they can fly. ( the writer isa skydiving teacher)

[Tdol]

A flying stone would just go through the air then fall, while a bird can change direction, go up and down, etc.

[sandhya.sha]

A flying stone would just go through the air then fall, while a bird can change direction, go up and down, etc.

Probably it means, they can do the actions on their own, like a bird which doesn't need an external help to fly. for a stone to fly, someone has to throw it.
does that sound fine?