It's powerless to fly! (6)
I believe the answer is:
glider
'it's powerless' is the definition.
I can't tell whether this definition defines the answer.
'fly' is the wordplay.
I cannot really see how this works, but
'fly' could be 'glide' (gliding is a kind of flying) and 'glide' is located in the answer.
A single letter 'r' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for glider that I've seen before include "Girdle for silent flier" , "Unpowered plane" , "Plane supported by air" , "Powerless aircraft" , "Motorless plane" .)