One with stamina needed when talking about flight (6)
I believe the answer is:
stayer
'one with stamina' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for stayer that I've seen before include "Horse with endurance" , "One not easily giving up" , "Long-distance runner, rather than sprinter" , "One that can last the course" , "Person with perseverance" .)