The most common and most likely answer to this crossword clue is the 2 plus 3 plus 3 letter word IN THE AIR
I've seen this crossword clue in Financial Times
I
N
T
H
E
A
I
R
More clues leading to the result IN THE AIR
- Article put out on home brewing
- Vaguely prevalent part of tune?
- Where balloon races are happening soon?
- Unsettled on a flight
- Flying is not yet fully developed
- Prevailing but undecided when following up
- Where a bird may be on everyone’s mind
- Looming, like a helicopter perhaps?
- Unsettled when flying?
- Unsettled on a flight
Buddy explains!

The straight part
We know that "Where balloon races/happening soon?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case where balloon races/happening soon? = in the air.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.