The most common and most likely answer to this crossword clue is the 2 plus 6 letter word IN FLIGHT
I've seen this crossword clue in The Times
I
N
F
L
I
G
H
T
More clues leading to the result IN FLIGHT
Buddy explains!
The straight part
We know that "taking up" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case taking up = in flight.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 IN FLIGHT mean?
IN FLIGHT adjective- Occurring, or provided for use during a flight