The most common and most likely answer to this crossword clue is the 9 letter word FALCONERS
F
A
L
C
O
N
E
R
S
Buddy explains!
The straight part
We know that "those who train fliers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case those who train fliers = falconers.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does FALCONERS mean?
FALCONERS noun- A person who breeds or trains hawks or other birds of prey for taking birds or game.
- One who follows the sport of fowling with hawks.