The most common and most likely answer to this crossword clue is the 7 plus 4 letter word NAUGHTY STEP
I've seen this crossword clue in The Daily Telegraph
N
A
U
G
H
T
Y
S
T
E
P
Buddy explains!
The straight part
We know that "Seat on flight for young miscreant?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case seat on flight for young miscreant? = naughty step.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.